"They were Gods once, but their worshipers either died out or were converted to the worship of other Gods. They wail and flutter around the edges of reality without substance or even thought. All they have is need. ... We go out of fashion, Sparhawk—like last year's gowns or old shoes and hats. The Powerless Ones are discarded Gods who shrink and shrink as the years go by until they're finally nothing at all but a kind of anguished wailing."
In the world of fantasy, it is a largely accepted fact that the power of any given deity is proportional to the amount of belief in them or the amount of worship they are currently receiving.
The deity could have been originally conceived and shaped by the needs and desires of one small group but like any good meme, this 'idea' grows with each new person who responds, then spreads the word of this great new 'god on the block'. Soon, the deity has enough collective belief behind their 'name brand' that they come into existence, and use that power to fulfill the needs of their worshipers. In this sense, a god is a form of Tulpa, a thought form, made completely out of their worshiper's belief and faith in them.
The opposite is also true: As a deity's power base of worshipers shrinks, their divine strength fades and if all worship of them ceases, they may completely fade out of existence. The tragedy here is that worshipers who leave the god because he/she didn't grant their miracle will continuously weaken the god until they can't grant any miracles. It's kind of like a bank run on a god.
In a similar manner, the well-being of an Anthropomorphic Personification is often tied to whatever concept they personify. Big concepts like Fate or Death are pretty safe, but Disco is in critical condition.
A subtrope of Clap Your Hands If You Believe, which can be used to explain why Powers That Be care whether or not anyone worships them. In games where you play as a Physical God, this is often used as a game mechanic to explain why you can't just Deus ex Machina your way through everything. It can also be used by authors as a Take That against organized religion. Compare I'm Not Afraid Of You, where smaller Anthropomorphic Personifications can be destroyed through disbelief.
Depending on the setting, the gods can often provide incentives for people to worship them. The gods of most typical Dungeons & Dragons games grant divine spells to their priests, which give them all kinds of fancy powers. Mortals and gods then end up in a symbiotic relationship, with the humans providing belief and worship to the gods and the gods providing assorted divine miracles in return.
This trope is related to Emotion Eater, but doesn't imply evil, vampirism, or negative emotions unless the god is tied in with those by nature. In belief systems of this kind, the empowered god often gives power back to his worshipers. Contrast Stop Worshipping Me, for when the god hates the worship they get.
This trope is dependent on a Physical Religion to entice prayer in the first place.
Named for Gauntlet's "<character>needs food, badly!" catchphrase.
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Very important in Kannagi. As traditional faith dwindled the sisters have been losing their powers to the point where they are fighting over the remaining faith power. Nagi's sacred tree which once sustained her has been cut down, and Zange's is inside a church, further dwindling / altering their powers and conditions. Zange has been taking on Christian aspects and resorting to setting herself up as a pop star to gain "faith" in the form of fans. The more believers they get, the more powerful they become.
In the end of Pita-Ten it is revealed that angels' and demons' existence depends on human faith in them, and once some entity is forgotten it ceases to exist which is a way to kill demon or angel, however if memory is restored it is possible to revive a dead demon or angel. Strangely enough these virtual creatures have quite strong real powers and can manipulate human memory as well.
In the Slayers world, the dragon gods gain strength from praise and worship, which is in contrast to the opposing Mazoku who feed on human suffering. This plays a role in a war between one of the gods and the Mazoku race that occurs a thousand years in the past from Lina's time. The Mazoku crippled the Water Dragon King by killing all the worshipers and destroying all the temples dedicated to the latter.
The second episode of Natsume Yuujinchou has a very poignant example of this trope (that also doubles as a Tear Jerker) when a Youkai that took up residence in a roadside shrine begins to lose his power (and his tether to the living world) as the people who once prayed to him all begin to die of old age. Natsume himself offers to pray to him but the Youkai refuses saying: "It's impossible, because you are my friend."
A key theme in Serial Experiments Lain; Masami Eiri defines godhood as this, and the main thrust of his scheme is ensuring he will have people believe him to be God, so that for all intents and purposes he will be.
Fanon of Axis Powers Hetalia has it that the Nations are born when their national identity begins to develop, and "die" when no one identifies with them anymore.
This theory rather strongly brings into question Canada's existence but would explain why he is much weaker than his twin.
Shown in Nurarihyon No Mago when Senba, a god of healing, feared he would fade away and disappear because no one visited his shrine anymore.
A major point in Naqua-Den as the Gods need prayers for power in order to fend off threats from malicious or corrupt Gods. But since most people in the modern era don't believe or worship them like they used to anymore, Nakua has to find ways to get them to do so.
In Noragami, the more worshippers a god has, the greater their power. Main character Yato is hoping to become the most revered deity in the world, even though he's just a shrineless vagrant who waits on cell phone calls for jobs. He's reduced to granting wishes for ¥5, whether they be finding a lost cat, cleaning a bathroom or breaking a curse.
In general this applies more to DC than Marvel. In Marvel the abstracts are not usually called gods and transcend them. More traditional gods like Thor and Ares have not been worshiped on a wide scale for centuries. They don't complain about loss of power or seek out new worshipers. They show no loss of power over time. Some writers have shown a connection between mortals and gods, but generally this is more a cultural connection that allows gods to interact on Earth instead of a dependency on faith.
Some entities, usually malevolent entities, that are worshiped as gods in Marvel really do derive power from it- Dormammu, for instance, has his energies constantly replenished by worship throughout the universe, while the Elder God Set once gained power not from worship per se, but by violence committed by certain species he was connected to (such as the dinosaurs). However, in both cases their power is more like Mana- using their powers costs them magical energy, and they only need rest to replenish it (though Dormammu also gains strength from annexing other dimensions). On their own both are as strong or stronger than even the likes of Odin, who is the strongest "regular" god there is and can affect things on a galactic scale- worship simply means they don't have to worry about tiring themselves out.
DC gods tend to be more vulnerable to this. It is usually used to justify Ares being a major threat to even the combined Olympian gods and why he constantly spreads war. Several storylines have had Ares and other gods be stronger than Zeus due to changes in worship and things mortals venerate. A lot less people are afraid of the sky or praying for rain than they used too. However, power tends to rely less on direct worship and more on how important the concept a god represents is to the mortal world. Ares can feed on conflict of any kind instead of that just dedicated to him. There are exceptions. The New Gods tend to stay strong without a race to draw strength from, but at times they have implied to be more gods of technology that draw power from across the universe.
Actually, they are the gods of Ideas- Darkseid, for instance, is the God of Tyranny. Incidentally, he is the only god worshipped on Apokolips and he is far more powerful than all of his minions, each gods in their own right. However, this has nothing to do with how many worshipers he has- he has instead been periodically slaughtering entire pantheons of gods of other worlds and stealing their power for himself, and he was amongst the strongest New Gods before doing that anyway. The New Gods do not seem to ever depend on worship for their power.
In fact, New God Orion was very emphatic about this in his series - when rather pathetically confronted by a defeated enemy with this notion, he replied "You have been reading too much fiction. Gods are not dependent on their worshipers - worshipers are dependent on their gods."
In the Fear Itself crossover, Iron Man mocks, invokes, and turns this into one helluva Tear Jerker. He started screaming at Odin and the other gods (but mostly Odin), yelling that if they wanted a sacrifice he'd give them the "only thing he could give worth anything": his sobriety, by taking a huge swig of alcohol. Even though it was a Narm scene, it was effective to the fans who know how hard he works to stay sober.
DC has this apply to Uncle Sam, whose power is directly proportional to the American People's belief in freedom and liberty. Whether American protectorates like Puerto Rico, Guam, and the Virgin Islands' people's belief in freedom and liberty counts towards this is never specified.
Thor once discussed this with Captain America. Even he's not certain whether his existence depends on mortal belief, and wonders if he will just vanish when people no longer need him.
Prior to the New 52 reboot, DC villain Eclipso tried to kill God by destroying the focal point of the worship that sustains Him: Earth.
The Sandman had gods born from dreams and when they were forgotten they would return to the world of dreams to eventually fade away. Lucifer followed a similar idea. The goddess Bast is a shadow of her former self. Ishtar had to become a stripper. Pharamond changed his role and became a minor god of transportation. The Japanese gods absorb articles of faith from other pantheons and modern times to survive. The Norse gods appear to be doing pretty well though.
In fact, Neil Gaiman frequently reminded readers that The Endless are not gods, because they do not care if they are remembered and will persist long after humanity is gone. They really are Death, Dream, Despair etc, and their existence depends on these aspects of the universe rather than mythology, and not just on Earth.
In Knights of the Dinner Table, after Bob's character, Knuckles III, dies, his next character (Knuckles IV) manages to get Knuckles III promoted to gawdhood. Temples to Knu-Kyle-Ra are now a recurring feature in the comic. Unfortunately, they don't owe Bob's other characters any favors.
In My Faith In Frankie, gods gain power from the belief of their followers. Judging by Jeriven, they only need one true believer to be at full strength, but more may have more effect.
In one of the later Savage Sword of Conan comics, Conan's physical likeness to a hero-turned-demigod is exploited by a local tyrant looking to put down a growing rebellion and win droves of recruits to his army. (Said hero, Shan, had once promised to return to his people one day when their suffering became intolerable.) This becomes problematic when the actual demigod shows up on the battlefield and strikes down everyone who participated in the fraud, except Conan. Impressed by his bravado, Shan decides to slay Conan in hand-to-hand combat. Clearly outmatched, Conan undermines Shan by questioning his motives, pointing out that if he really cared about the welfare of his worshippers, he would have freed them from the tyrant long ago. He only appeared on the battlefield because he was in serious danger of losing their adulation. Conan's words make Shan's followers question their belief, which actually de-powers the deity. Conan finally disarms him and runs him through, forcing Shan to retreat to the realm of the gods, now deprived of the worship needed to sustain him.
Averted by Crom. He's liable to kill anyone who dares pray to him, as it implies his gift of life and the will to do battle was not enough.
The universe of Asceltis (in French comic books Les brumes d'Asceltis and Les exilés d'Asceltis) embodies this trope. It is quite scary to see what Gods can do to keep people believing in them.
In the X-Men comics, the Dimension Lord Mojo's magic powers are tied to the number of people who pay him homage, which they do by watching his TV shows.
The Greek gods in The Red Seas are like this; on the Isle of Bronze, there are a group of massive statues originally built by Hephaestus in order to absorb faith and thus recharge the gods. For some reason, the Norse gods don't need faith in the same way. Satan also seems fine, but that's likely to be because most people do believe in him.
While it's likely not an issue for the true God, this is how The Demon came to reach his current level of power in Grimm Fairy Tales. In the beginning he was one of the weakest of all demons, but he was the first to realize that human prayers contained power, and it quickly took him From Nobody to Nightmare.
Harry Kipling (Deceased) works this way, with some creative upshots from Simon Spurrier. For example, since Klux was made from Kipling's tissue, Klux considers Kipling to be his creator and thus a god. Gaining a single worshipper means that Kipling is technically a god, and thus is able to kill other gods. Also, the New Atheist Militia realise they can destroy gods by massacring their followers, and their denial ultimately manifests as an anti-god which operates much like any other deity.
In Lanfeust, the Darshanide Gods need believers to exist. The first time the heroes visit the divine court, they witness the goddess Lynrenö fading into nothingness as her last believer dies.
There's a Buffy the Vampire Slayer fic that deals with the gang visiting a realm that serves as a home for the forgotten gods to seek help from Ares. While there Ares comments that two of the gods don't really belong there since they seem to have plenty of followers, a South American god still worshiped by natives, and even more strangely, a norse god who seems to have gained power in the last century.
Another fic has as a subplot Illyria becoming a famous singer with a rather rabid fan base; according to the God-King, they actually work better than modern day worshipers.
Discussed and generally averted in Undocumented Features. Corwin, an ascended Physical God, seems to have no need for anyone to worship him, but that doesn't deter Chip, his self-proclaimed first worshiper, from doing so. Corwin's admonishments of Stop Worshipping Me have gotten to the point of gentle admonishment/Running Gag.
Goddess Reborn Chronicle, sort of. Given a high amount of Unreliable Narrator, it's unclear how much effect belief and prayer have on demons but it clearly has a high importance. The rise of Humanism for instance is explicitly spelled out as part of why Veritas is doing so well, as well as the spread of Gnosticism, Buddhism, Neo-Paganism and belief systems that believe in choice and humanity's ability to rise above on their own merits and transcend the ordinary.
In Q: The Winged Serpent, the Aztec god Quetzalcoatl is prayed back into existence and begins terrorizing New York City in the form of a giant flying snake-bird thing with four legs. Incidentally, Quetzacoatl was one of the more benign Aztec Gods.
While God, angels, and demons in Dogma apparently exist independently of humans, they are still influenced by the way humans believe in them. This is made more explicit in some of the deleted scenes.
In Elf, Santa's sleigh is said to draw power from children's belief in him. Lately that's been dropping, so he relies on the assist of a modern combustion engine.
Zeus: Perseus and Andromeda will be happy together. Have fine sons... rule wisely... And to perpetuate the story of his courage, I command that from henceforth, he will be set among the stars and constellations. He, Perseus, the lovely Andromeda, the noble Pegasus, and even the vain Cassiopeia. Let the stars be named after then forever. As long as man shall walk the Earth and search the night sky in wonder, they will remember the courage of Perseus forever. Even if we, the gods, are abandoned or forgotten, the stars will never fade. Never. They will burn till the end of the time.
Played with in the remake of Clash of the Titans. Zeus and most of the Olympians sustain their immortality through the prayers of humans. This provides a problem when humans not only stop worshiping Olympus, but actively try and starve the gods of badly-needed prayers through blasphemy. As one would expect, it doesn't go well... especially since Hades doesn't need people to pray to him. Hades draws power from people's fear of death.
In the sequel Wrath of the Titans, prayers have dwindled so much that the gods have all lost their immortality and many have died before the movie even started. They still have most of their powers, but they are fading.
In Freddy vs. Jason, Freddy needs people to fear him to be able to infiltrate their dreams, so he became powerless when the inhabitants of Springwood systematically eradicated any trace of his existence. He uses Jason as a pawn to reinvigorate the locals' belief in him so he can return.
In Rise of the Guardians, the Guardians (and other beings), cannot be seen or touched by those who don't believe in them, and are weakened by lack of it. This becomes a problem when Pitch Black, AKA the Boogeyman, attempts to destroy children's belief in them, as he is tired of children not fearing him, at one point weakening Bunny to the size and shape of a regular rabbit.
Adam R. Brown's Astral Dawn series plays with this trope through the high spirits. Many high spirits became gods during a period called the God Age. The psychic energy they received from their followers made them even stronger than they had become. All high spirit gods, be they light or dark, are beyond normal space-time, allowing them to feed off of their worshippers from a specific time period. This means they never need to worry about their worshippers decreasing or dying off.
The Dresden Files use this with a few unique ripples. Spiritual entities need some level of recognition to operate on Earth. Thus the various old gods (with a little 'g') have very little ability to act on their power. This is laid out in info concerning the Venatori, who fight the Oblivion War, trying to get all memory of magical entities removed from the human psyche, and therefore cut their connection to the material world. Need-to-know basis doesn't even begin to describe it. But now you know, so now they have to kill you. Smooth.
Also evidence suggests that this doesn't apply to God (with a big 'G') and His assorted Archangels. Not that it would really matter if He did need prayer, given how many believers He has.
Interestingly enough, the other God we've met so far (Odin) seems to have plenty of power, despite not having that many followers. He doesn't come close to the Abrahamic God in power (at least, as far as we've seen) but he can still throw some weight around. (That said, it is implied that Santa Claus is an aspect of Odin, and Santa Claus, even if he doesn't have many real believers, is a pretty big influence nowadays...)
It should be noted that they do not cease to exist with lack of worship. They can still be active in the spiritual realms and other dimensions. Recent books have implied that how humans perceive the universe is very limited compared to gods and other supernatural creatures. To humans, the god might be inactive, but they are still active in other ways. Many of these entities predated humanity and it is unknown how they came into contact with Earth or if the ever changing rules of magic had anything to do with it.
In The Devil's Apocrypha, in which Satan Is Good and God Is Evil, God manipulated evolution on Earth to produce sentient humans in his image. He then advises us to commit brutal, violent acts in his name - the faith gives him nourishment. Satan and his followers, meanwhile, stand for free will and moral justice, and advise us not to mindlessly obey God and be reduced to his sheep.
Fritz Leiber's stories of Fafhrd and the Gray Mouser have a unique take: all temples in the city of Lankhmar are located along the Street of the Gods. Less-popular religions are located at the end of the street closest to the city gate; the more numerous a deity's followers, the farther from the gate his temple is located. Religions ebb and fall up and down the street throughout Lankhmar's history.
In the A.E. van Vogt story The Book of Ptath, gods are powered by "prayer sticks," which are actual machines (albeit, Sufficiently Advanced ones) that are physically manipulated by their worshipers to send power to the god.
American Gods uses this as a central plot point. There's some major Fridge Logic (or perhaps Fridge Brilliance) at one point given the slighting way one of them refers to Jesus. Given that deities are powered by belief and sacrifice, he (probably along with Vishnu) would likely be the most powerful god around at present.
There's also the implication that each nation has localised versions of gods: the American Kali mentions that there is a much more powerful Indian Kali, the protagonist briefly meets an Icelandic Odin and a powerless Jesus in Afghanistan is mentioned.
David Eddings uses it in the Elenium and Tamuli trilogies (the source of the page header quote). At one point, the goddess Aphrael becomes ill because her worshippers are being killed.
Terry Pratchett uses this one a bunch throughout Discworld. The Discworld is lousy with small gods, most of them just "a pinch of existence," barely sentient and incapable of much more than disturbing dust or influencing the minds of animals. But the right minor miracle in the right place at the right time...
Small Gods concerns the rise, fall, and return of the Great God Om, patron deity of the theocratic empire of Omnia. He left at the height of his power, promising to return during the rise of the next prophet. When he does come back from his godly vacation, he finds himself inexplicably trapped in the body of a small tortoise, unable to conjure more than a spark of static. As it turns out, his followers began to believe less in him and more in his church, or more specifically that showing proper commitment to the church was less likely to have you tortured to death for heresy. By Om's return, only a single lowly acolyte believes in the actual deity Om rather than Omnianism.
The Last Hero introduces Nuggan, a minor deity hailing from Borogravia. An unpleasant god with an unpleasant mustache, he's a bossy little deity whose holy books are three-ring binders so he can constantly add to the list of Abominations that make life so miserable for his followers - when the Silver Horde brings a Borogravian bard to Dunmanifestan, they have to physically restrain the man from attacking his god. By Monstrous Regiment, the Abominations have helped cripple a war-torn Borogravia's economy (no more crop rotation) and have become so deranged (Abominating babies and the color blue) that citizens have taken to praying to the land's Duchess for succor. In the end, Nuggan is revealed to have faded away, with the Abominations as a sort of echo, while Borogravia's faith in its Duchess has given the now dead woman a quasi-deity status, much to her consternation.
The Last Continent features the God of Evolution, who has no worshipers. He exists because he believes in himself very strongly, or more precisely, what he does.
During Going Postal Moist Von Lipwig perpetrated a con that resulted in the border-line small god Anoia, Goddess of Things Getting Stuck In Drawers, seeing a sudden surge in popularity and a possible promotion to Goddess of Lost Causes. Moist prays to her on the basis that she owes him, and Making Money reveals that this may have paid off - the secondary villain suffers a sudden and disabling malfunction of his dentures when one of its springs gets unstuck at a critical moment.
In hindsight, the golden Guardian at the Gate (a.k.a. "He looks just like my Uncle Osbert...") from Moving Pictures was probably a god of some sort, as he needs people's remembrance, and by extension, their belief that he can protect Holy Wood from the Dungeon Dimensions, if he's to stay awake.
The gods of the Dragonlance setting don't die without worship, but getting it does make them more powerful.
Mercedes Lackey can't make up her mind on this one. Most deities in the world of Valdemar are actually just aspects of the God and the Goddess (and the One is implied to be both at once), whose power descends down to the clerics instead of the other way around, but in one vignette it's explicitly mentioned that a demon can ascend to divinity by running a sex cult and feeding off all the worship (and a few worshippers too). This inconsistency came about because the short stories that demon appeared in weren't originally part of the Valdemar 'Verse, but rather were retconned in later.
Tamora Pierce's Daughter of the Lioness series mentions this principle, although it's not necessarily the number of people who believe, but who's in power. The trickster god Kyprioth needs his followers to defeat the mortal followers of his siblings Mithros and the Great Mother Goddess in order to gain enough power to defeat them, return from the exile they imposed, and resume rule over the Copper Isles.
There is also a case of regional variance in power. The Graveyard Hag is a fairly weak goddess of trickery in most of the world. In her domain of Carthak her power is so absolute only her father the god of death can oppose her.
A variation on this occurs in Tanith Lee's "Tales From the Flat Earth" series, where most of the god-like "Lords of Darkness" derive themselves from humanity's understanding of abstractions; i.e. they start out as mindless forces, and over time, as humanity personifies them, they become actual entities with full-blown personalities. The actual creators of the earth, however, the Gods, are pretty much oblivious to humanity, and ignore prayers and offerings. The Lords of Darkness are often worshiped as Gods, though (this is a major plot point in the second and fourth books), and are about one level or so below the actual Gods in power. Azhrarn, the first Lord, and personification of Wickedness, is different from the other lords, in that he's older than the universe, doesn't need human belief to be personified, and is probably as old as the Gods, but not as powerful; though it is implied that human perceptions of him do "fluff up" his definition, or at least has some relation to how he manifests, but only slightly. However, it is strongly implied, if not outright stated, that without humanity, Azhrarn would lose his sense of purpose, even though he would still exist. The other lords, like Chuz, Lord of Madness, or Uhlume, Lord of Death, are explicitly the products of human imagination, do not predate the universe, and it is implied that they would fade away without humanity.
The End of Mr. Y by Scarlett Thomas: Gods are created by belief and, of course, gain power from worship. Apollo Smintheus, the mouse god, has a cult of six guys in Illinois with a website. As you might guess, he's not particularly powerful.
In For Love of Evil, Piers Anthony shows that YHWH used to have a lot of power, but since belief in the Hebrew God had waned, his place had been usurped by the Christian God.
Subverted in The Soldier Son trilogy by Robin Hobb. The main character attempts to denounce that he owes ones of the "Old gods" a favour, saying that he "Believes in the Good God - You have no power over me" at which point the Old God laughs and tells him "How weak do you think Gods are? Do you think we require your belief in us to exist, how weak would such a god be?"
Star Trek: New Frontier brought us the Greek gods (who were also the Roman gods, the Norse gods, etc.,) known as The Beings, who were kin to Apollo in the original series episode "Who Mourns for Adonais?" They eventually get all powerful thanks to the worship of the Danteri... and the fear of the Excalibur and the Trident. They're beaten by said crews becoming quite literally fearless, along with the help of Mark McHenry (the descendant of Apollo and Carolyn Palamas)... and Woden/Zeus/Santa Claus, god of all gods.
The short story anthology Gods of War (by Christopher Stasheff, et al) features this, but also indicates in addition to the Greek, Norse, and Japanese gods (among others) who fall into this trope, there is the 'one god' who is above the others and has no such concerns or limitations.
This is how it works in Dave Duncan'sGreat Game trilogy. Any "Stranger" — a human from another parallel world — can absorb power of human emotions and faith, use it for miracles and eventually become a "god". The balance of power in the world of Vales is being upset by one lesser god who has discovered a much more efficient means of getting divine power from worship — human sacrifice — and threatens to overthrow the major gods.
Played very straight in The Acts of Caine, but with a history. A long time ago, gods had whatever power they could draw from T'nalldion a.k.a. Home, the fundamental pattern/source of all magic on Overworld. Then this lowly human named Jereth got involved in a religious war, kicked some ass, earned the title of Godslaughterer, and died to establish the Covenant of Pirichanthe, which limits the power of all deities to what their believers provide. The exceptions are the [[E Outer Powers]] which feed on the suffering and fear of sentients, and the Blind God, who is happily nigh-omnipotent on Earth despite the fact that his worshipers neither believe he exists nor care.
Partly how gods are created in The God Eaters, where a human born with magic is worshiped until (at least in the case of Medur) they gain enough power to return after death. Eventually, however, they amass enough power that they don't need belief to keep going. Still doesn't mean they're indestructible, though.
Several short stories by Lord Dunsany explore this trope, most literally Poseidon, in which the eponymous deity complains that he can no longer cause earthquakes without the blood of bulls. Perhaps humans just got smarter over the years.
In the Book of Swords, when people find out gods can be killed, their faith is shaken. Eventually, it is discovered that humans created gods by believing... which they stop, destroying all the gods. This leads to the question of "If humans made the gods, where did humans come from?" (Inversion of a question often asked theists in Real Life.)
Yahweh, in The Salvation War. A lampshade is hung on it by an intelligence officer, who describes him as "Like the Ori." Satan, on the other hand, is collecting suffering in Hell. They are both collecting because they both have the unsubstantiated belief that they need more energy to Ascend to a Higher Plane of Existence since both of their universes are shrinking and will collapse eventually (in a few billion years).
Expanded by Dan Simmons in his short story Vanni Fucci is Alive and Well and Living in Hell, where different versions of Hell as well as God become true on the basis of the number of people who (consciously or not) believe in them. Vanni Fucci, one of the many people condemned to Dante's Hell simply because Dante did not like him very much, takes an opportunity to take over a televangelist's show and convince everyone not to believe in Dante's Hell anymore. Hilarity Ensues.
In Jennifer Fallon's Demon Child Trilogy, the Primal Gods are the ones that will exist as long as life exists (Love, War, the Oceans), and don't rely on human belief for power. They do gain strength through worship, but this doesn't entail praying (for example, "honouring Dacendaren" is a euphemism for stealing; Damin Wolfblade is favoured by Zegarnald, God of War, because he wins a lot of wars.) On the other hand, the Incidental Gods are demons that gather enough worshippers to become gods. The Big Bad of the series is an Incidental God that has gathered enough followers to challenge the Primal Gods' power.
In Harry Turtledove's Magitek novel The Case of the Toxic Spell Dump, this has become the province of bureaucracy; the EPA is responsible for creating artificial cults to sustain "endangered gods."
Maintaining artificial cults is as much a practical matter as it is idealistic; all of the magic is divine. One of the gods maintained by an artificial cult, for example, is Hermes, and spells calling on him are the basis for most of their telecommunications.
In this setting, it's especially clear that only worship will sustain a god: merely being acknowledged to exist doesn't suffice to keep them around. Thus, a pantheon of Chumash native deities can be dying out from lack of sincere prayers directed towards them, even though plenty of non-worshipers in the EPA are aware of their existence and concerned for their welfare as "endangered gods".
In Orson Scott Card's Enchantment, the old Slavic gods Mikola Mozhaiski and the Bear of Winter aren't killed by a lack of belief, but their concerns are much smaller and they try to live normal lives until they're needed again for godly duties.
Zeus is currently enjoying his retirement in the Caribbean.
In Simon R. Green's The Nightside Series, gods function rather like this. They even have harkers out on the Street of Gods trying to increase their base of worship to gain more power. Who often dissolve into shouting matches over who's dogma's right. It's a God eat God world out there...
Averted in the short story The Food of the Gods by Poul Anderson (in collaboration with his wife Karen.) Here it is stated that while worship - or at least reverence - is needed in order to achieve Godhood, once that state is reached the resultant deity is immortal, and no longer requires active worshippers. Some degree of continuing respect, however, is necessary if a God (or pantheon) is to have any continuing major influence on the mortal world. As an example, it's related by the god Hermes that when Christianity displaced Paganism, a dark age followed because the Olympians held too much of civilization within themselves. It was only when the Christian Trinity allowed Greco-Roman mythology to be rediscovered that the Renaissance became possible.
The Greek gods in Marie Phillips's Gods Behaving Badly have been holed up in a house in North London for a century or two, reduced to shadows of their former selves because the faith that made them powerful is now going to "the upstart carpenter" and his father.
C.S. Friedman's Coldfire Trilogy is set on a world where an occult force makes human imagination become real. Unsurprisingly, a number of god-beings start to appear who answer prayers in return for feeding on their worshippers' life-energy.
The zealot species Yuuzhan Vong of the Star Wars Expanded Universe seems to think this way: "The gods may have created us, but it is we who sustain them through worship."
Although with their creation myth (life was created through a terrible wound inflicted on its creator), this could instead refer to the expression of their worship through omnicide returning the gift of life to the gods.
A dark variant of this exists in the Malazan Book of the Fallen. Ascendant, mortals who transcended their limited existence to achieve a sort of demi-godhood, are generally weaker than gods who have secured large followings. Those gods gain strength, master the Warrens, and become even more powerful. Yet at the same time, accepting worship binds them to their followers, sometimes even distorting their nature and actions as the prayer imposes demands upon them.
In Laurell K. Hamilton's Merry Gentry series, the main characters are fairies, and referred to repeatedly as deities or former deities. Those who are still believed in [e.g., Frost] grow in power, and those who are no longer believed in diminish. There are also characters who exist as a sort of vampiric ghost of gods whose worshippers have died out, referred to as the Starving Ones - they are responsible for several slaughters, increasing in scale, in one of the books, as they use the energy to attempt to rebuild themselves.
The Fey are touchy about this, as most both believe in the existence of higher powers (which have no need for worship) and that they never were gods, seeing the collapse of most of their power (causing them to watch the deaths of the worshippers they could no longer care for) as punishment for the hubris of ever thinking they were. At the same time, they are influenced by human attitudes, and can feed off human notice, admiration and attraction. Also, by now the title character technically has a few human worshippers.
Warbreaker has an unusual take on the trope: the Returned subsist on what are effectively human souls (Breath) that must be given willingly. Thus, Returned need people to believe in them enough that they would willingly give up their souls to see them live another week.
In this case, it helps that the Returned can, in turn, give away their own Breath - albeit at the cost of their life - in order to heal someone. Additionally, any person who gives up their Breath for one of the gods recieves generous financial compensation.
In the Iron Druid Chronicles the gods have their own sources of magic and don't really need to be constantly worshiped to remain powerful, but active worship is required for them to be able to physically manifest, and the way people believe in them shapes their appearance when they do.
Jesus does not like to appear to people because he would have to appear nailed to a cross and it's a very painful experience even for a deity. Mary's appearances are much more frequent and often triggered by the belief of old devout ladies.
Complicating matters is the fact that if two groups of believers in the same god diverge enough in their beliefs, the god will split into regional aspects. There are dozens of versions of the Native American god Coyote running around. The Thor from American comics is brought up a few times, but according to Odin 1.0, he exists only as a concept. Without worship he doesn't have enough magic to manifest himself.
Perun's grudge against Thor was him blaming Thor for being forgotten and weakened in power. Yet in actual practice did not appear any weaker. On the other hand, Jesus is the most powerful known supernatural being and one of the most widely worshipped. So as a whole the series flip flops on how much gods need prayer.
In “Oblations at Alien Altars,” the introduction to Deathbird Stories, Harlan Ellison makes the point that for all their seeming puissance, gods are a remarkably fragile lot (although in one of the included stories he acknowledges that the truism is Nietzsche’s). He writes that “When belief in a god dies, the god dies.” Several of the stories address that idea.
This is the rule that underlies the metaphysics of John Scalzi's novella The God Engines. The more worshipers a god has, and the stronger their faith is, the more powerful the god gets. It also puts a couple of twists on the idea - first, gods get more power from worshipers who converted from another faith than from people who "inherited" the religion, and more still from worshipers who convert from atheism. The main character's god even keeps planets sequestered from all religion as a sort of "atheist farm," just so they can be converted with a quick miracle to provide a power boost when needed. And second, gods can eat souls to get even more energy from each person, although even other gods consider that a Moral Event Horizon.
This is the case in Roger Zelazny'sDilvish the Damned. Specifically in Devil and the Dancer short story the last worshipper of an almost-forgotten god is very important to him and he has to do the things she wants, even if he finds them revolting. It works in the opposite direction too, The Big Bad Jelerak has been mentioned in evil spells so many times, the mere mention of his name can summon dark spirits.
For the most part averted in the Percy Jackson and the Olympians book series. The Olympians have not been widely worshipped in centuries and have not suffered any major loss in power. The Titans were sealed in Tartarus for thousands of years and survived. The almost unheard of snow goddess Khione is doing fine. However, there is some link. Its been stated that if Western Civilization were to fall it would weaken the Olympians. Being forgotten can cause a god to lose their will to live leaving them to fade from existence though like Khione or the Titans it is largely a matter of personal will. The god Pan tried to fade two millennia ago, but the beliefs of nymphs and satyrs caused him to continue to live.
Live Action Television
Xena: Warrior Princess implies this, rather than it being outright stated. The Olympian Gods (the primary pantheon dealt with on the show), were shown to have a reach and influence as far as the Middle East, and were considered the greatest of any gods in the show, while others were shown as powerful, but not nearly on the Olympian scale. The show attributed it to less worship, and Ares even remarked to Kal once that his (Kal's) temple, and power had gone down hill since "those tributes stop[ed] coming in". In some episodes set in the modern day, Ares is a lot weaker than usual because modern day people don't usually pray to him.
The initially conventional Christian-themed horror series Brimstone, in which a damned policeman is given a second chance at life by Satan in return for tracking down 113 souls who had escaped from Hell, undergoes a dizzying Genre Shift when the LAPD policewoman who had been his inside track with Earthly authorities is revealed to be the ringleader of the souls, a dead Canaanite priestess who had engineered the escape from Hell by seducing Satan. (The policeman had, unwittingly, been helping her to eliminate members of her "gang" that had gone rogue.) Her plan is to systematically eradicate belief in the God of Abraham from human culture, thereby causing God, Heaven, and Hell, to all blink out of existence. The protagonist realizes that Satan had been desperate to retrieve the escaped spirits, not out of some altruistic desire to restore the Cosmic Balance, but because if the priestess were to succeed in her agenda, Satan, being part of the Abrahamic mythos himself, would blink out of existence as well. Naturally, just as the series threatened to actually become interesting, the network pulled the plug.
The Merlin TV miniseries explicitly says that creatures like Mab and the Lady of the Lake only exist because people believe in them. Once Christianity moves in and people don't believe in magic, it doesn't exist any more. The climax has Mab literally fade into thin air because the crowd turn their backs on her and move on with their lives.
The Ori gain power from human worship, although they're still extremely powerful on their own. Once Adria takes their place in The Ark of Truth, SG-1 needs to take away her worshippers to make her vulnerable.
The Ascended Orici Adria, being the focus of everyone's worship as the last remaining Ori, is too strong for anyone to challenge. However, once the Ark of Truth is deployed and the Priors stop believing in her she loses a significant bulk of that power, opening the way for an Oma Desala gambit.
In Valentine, it's said that it isn't so much prayer or belief that the gods need as it is "relevance." What this means for the main characters (Aphrodite, Eros, the Pythia, and Hercules, disguised as humans running an LA matchmaking service) is that if they don't do a better job at uniting soulmates, they'll cease being relevant to humanity, and will consequently lose their immortality.
In one episode, the guys come across the haunting that wasn't - it was just a practical joke. The prankee buys it and posts the story on the internet where it becomes well known in a Urban Legend kind of way. Once enough people believe that there is a ghost there it actually appears. It was defeated by writing a weakness into the text - once enough people believed it, the ghost was defeated that way.
In the Christmas Special episode of season 3, the brothers run into two old Gods who are kidnapping people and sacrificing them to themselves. The couple boast that they use to be so powerful people would make sacrifices to them daily, but time moves on and they've assimilated themselves into modern culture and now only kidnap a couple people a year to sacrifice and keep themselves going.
The original Star Trek episode "Who Mourns for Adonais?" involves a cosmic entity claiming to be the Greek God Apollo, who says that his fellow gods faded away as humans stopped worshiping them. He tries to force the Enterprise crew to worship him, but their resistance to the idea ultimately convinces him that humanity has indeed outgrown him, and he chooses to fade away himself.
Heroes season 4 Big Bad Samuel Sullivan is a super whose geokinetic powers become stronger if he is surrounded by other supers who believe in him. In theory he could break the world if he had a large enough crowd of supers nearby. His brother Joseph hid the true nature of Samuel's power from him and deliberately limited the size of their super carnival to prevent Samuel from becoming too dangerous and Samuel killed him when he found out the truth. Samuel is eventually defeated when his fratricide is brought to light, causing his fellow super carnies to lose faith in him, and Hiro teleports them away. Samuel is left all alone in an empty carnival as a powerless, broken, shell of a man.
A recurring theme on MythQuest. In episode 4, the myth they visit is set in motion by spirits attempting to ensure the survival of the aboriginal people who worship them. Cleo then has this opinion about that myth as a whole, and to an extent, mythology in general.
Mythology & Religion
A Greek myth/folktale likely written in Christian times by Plutarch times tells of the death of the god Pan when people start thinking of him as only a made up story. One might wonder about the rise of Neo-Pagans, who have begun worshipping of Pan again. Have they resurrected him, or is their belief going unheard?
In Islam, this trope is rather clearly averted for much the same reasons.
The Neopagan scholar Isaac Bonewits describes gods as functioning basically as the trope says. He's not alone; this theogony is quite common, especially among Wiccans and Asatru (Norse-pagan revivalists).
This trope is fairly common in real-world polytheisms, especially those with a substantial animist or pantheist component. Among modern religions, it is especially significant in the religions of the African diaspora in the New World (Vodoun, Santeria, Candomble, Umbanda), and in the Shinto animism of Japan. Historically it was an important though implicit idea in Hellenic- and Roman-era syncretism.
In a way, there's a "Person Needs Prayer Badly" in medieval European Catholicism... in order to go to Heaven (or reduced their time in purgatory) and join the Angels, the soul of the deceased needed to be prayed for. This led to the modern idea of the funeral—particularly how the modern Western funeral is such a huge deal—as well as other ideas.
It is still part of the Catholic beliefs, but you only pray for the soul in Purgatory as man has no role in deciding the salvation of souls.
While not all religions believe that their god(s)' power and influence increase in proportion to the number of worshippers, there is no denying that it has this effect on the religion itself. You say the wrong thing to a member of a religious order that has enough clout, you WILL believe in divine retribution.
Maltheists (those who believe in God, but believe that God Is Evil) often believe that God will die if nobody worships him. Which is what they hope will eventually happen, because they believe humanity cannot truly be free until God dies.
The state religion of the Aztec or Mexica Empire believed the gods are always hungry — not for belief or prayer, but for human and animal sacrificial victims — and that if they were not fed a steady diet of the hearts of brave warriors, they would surely destroy the world, as they had many times before. The whole Aztec political system was designed to prevent this by waging enough wars that there would always be plenty of POWs to sacrifice; in some cases, Tenochtitlan and another city-state would stage a set-piece "Flower War" with no objective but giving each side a chance to capture some of other's soldiers for sacrifice. (Not every state the Mexica forced to participate in this seems to have shared their level or form of piety on the matter — a circumstance Cortez, when he arrived, found very useful to his purposes.)
To put it more bluntly, many of the Aztecs' neighbors, and particularly the less pious ones, saw them as a mixture of The Empire and The Religion of Evil, seeing as the Aztecs had a habit of capturing whole villages for sacrifice and then moving into the vacated homes.
In The Epic of Gilgamesh a character recalls the gods "crowding like flies" around a sacrifice after most of mankind is destroyed.
In one of Patton Oswalt's bits, he hypothesizes that this is true. His wife tells him that she saw a rat at their house, and he doesn't believe her, and assumes she saw a squirrel. He then sees the biggest rat ever crawl across the telephone line in their backyard, get picked up by a hawk, and then get dropped by said hawk in the neighbor's yard, scaring their children, all in 60 seconds. Patton then says that maybe that weird sequence of events was due to a forgotten Sumerian trickster god.
Patton: Is there a forgotten Sumerian trickster god, and his feast day is July 3rd, he's got one worshipper left, and the dude killed a goat over a copper bowl, and it gave the god 40 seconds of power in our realm. He just poofed into being.
In the Forgotten Realms, a god's power is determined by his/her number of worshippers, and needs at least one worshipper to maintain Divine status (albeit at a demigod level). The only exception is the overdeity Ao, who needs no worshippers to maintain power because he rules over all of the universe. This development took long to come, as the deities were independently powerful before the Avatar Crisis, when Ao got fed up with nobody doing their duties or taking care of their worshippers any more. The post-Avatar Crisis fluff tended to suggest, when the subject came up, that the Gods did gain power from being prayed to and having followers before the Crisis. What Ao did after the Crisis was, essentially, toning down the power you gained from your Portfolio, and ramping up how much power you gained from beliefnote this may explain how Myrkul got the idea for the Spirit-Eater Curse failsafe despite the Avatar Crisis not having occurred yet at that point.
In basic D&D, the Immortals need at least some worshipers or they fade away. They can come back if someone starts worshiping them again for some reason. A new Immortal can survive on power from his sponsor for his first year or so, but he'd better have found some worshipers by then.
Averted in Dragonlance, where the deities do not need any worshipers to maintain their power. They do need mortal followers to have much influence in the mortal world however, but they will not die from a lack of followers.
Also averted in the Greyhawk campaign setting. Several of the greater gods hold their exalted station despite people not being very inclined to worship them. Boccob "The Uncaring", god of magic, is completely disinterested in being worshiped, and in turn very few people actually worship him. Nerull "The Reaper" and Incabulos, god of disasters, likewise do not get a lot of attention, if only because most people fear attracting their notice.
Baldur's Gate being mostly canon to mainstream D&D shows us that a dead god can still exist if it's followers are still undead echoes, believing they must live for eternity guarding the temple of a dead god, which at the same time creates a demon of hatred to fight their dead God, time and time again in an endless cycle, akin to Ragnarok. The God wouldn't be without it's Guardians, and the Guardians wouldn't be without their God, thus both perpetually creating a Living Echo of each other.
In Demon The Fallen demons need faith to fuel their powers. They can either force steal it, which causes spiritual damage, or set up cults of various stripes to get a small but steady flow without necessarily hurting their worshippers (unless they want to be hurt).
This setting has the Astral Realms, which include the Temenos, the collective consciousness of humanity. Among the conceptual archetypes present there are every god ever worshipped. In this case, since they are formed through human belief, their power is proportional to how much humans regard them, not necessarily through worship. For example, Anubis exists in the Temenos, and though not as powerful as he was when he was actively worshipped by a powerful nation, he is still a relevant and well known symbol, which means he still possesses the power of a minor god. Other gods are less fortunate. Since the Temenos is a focal point for all human knowledge and experience, even a completely forgotten god would still exist somewhere, albeit significantly weakened. Its also suggested that some Temenos gods might be based by humanity on truly divine beings (a theory particularly popular with devout mages who suffer crises of faith upon learning they can meet their deities in the Temenos).
Similarly, various spirits in the Shadow realm are often shaped and empowered by human belief. Whether a particular one appearing as a god was an inspiration for human worship or was formed by human worship is often unclear.
The Chaos Gods in Warhammer and Warhammer 40,000 are both formed and fuelled by the concepts they represent. On the other hand, they don't really need prayer: every feeling of anger, ecstasy, hope, or despair feeds one of the Chaos Gods, whether the person who has the feeling is a follower of Chaos or not. Background material indicates this is the same for all deities, except for the God of Atheism, who gets strong if people don't believe in anything.
It is speculated that the Emperor of Mankind's almost militant atheism and denial of any superstitious talk of "daemons" was a direct attempt to starve the Chaos Gods of belief. While this effort obviously failed, the Imperium's faith in the God-Emperor of Mankind may have helped him become a proper deity himself, enhancing his already-formidable psychic presence and giving humanity a fighting chance, and it must be mentioned that the Horus Heresy is the only documented time when all four chaos gods got off their collective behinds and actually seriously worked to affect the galaxy at large, so the Emperor might have had something right to scare them that way.
Exalted: not only do Gods little and big benefit from worship as the currency of Yu Shan, but anyone can earn Essence if they get a Cult worshipping them. Something many player characters will find handy.
Or the opposite, depending on the campaign: if you start the game marked for death by beings whose job is strongarming gods (which is normal), having a higher profile and more ways to be attacked make it a mixed blessing at best.
The game spends quite a bit of time and wordcount examining the ramifications of this trope, too. Gods in Exalted are, by and large, jerks who want to get as much power as possible, and in Creation, this usually translates to theological feudalism: the strongest local god receives prayer and sacrifice, and in return doesn't cause the harvest to fail and doesn't let dangerous interloper gods take over the region. The Immaculate Faith, the religion of the Realm, isn't just about getting prayers to the appropriate gods, it's also about preventing gods from getting greedy and extorting extra worship out of the Realm's mortals.
In Rifts, Gods are naturally more powerful in their own home dimensions, and ones where they have a strong base of the devoted, than in any other dimension.
Before coming up with Magic: The Gathering and acquiring TSR, Wizards of the Coast released a supplement called The Primal Order to provide formal system-independent rules for deities and ways they interacted with mortals and each other. As described, all gods had a certain amount of power at all times (unless deprived of that by suitable attacks, at which point they could expect to shortly cease to exist barring possession of a loyal home plane to regenerate from over the course of a century), but gathering worshippers both living and dead as well as acquiring planar real estate and spheres of influence all provided significant boosts that only the strangest gods would want to do without.
Regarding Magic: The Gathering itself, the God cards of the Theros block qualify. These beings are indestructible, Legendary Enchantment Creatures, but if the god's controller doesn't have a strong enough devotion to that god's color (or colors) note Measured by the number of colored mana symbols in the mana costs of permanents that player controls, they cease to be creatures altogether.
This is the status for the gods in the Scarred Lands campaign... except for Chaotic Evil Vangal, who derives his power from how many people his worshippers slaughter. Otherwise, he would've died, since most people aren't too keen on worshipping a Blood Knight who doesn't even pretend to have any other motive besides fun.
In Scion, a character's Legend rating represents how well-renowned an individual is, and determines the strength of his divine powers. Full-blooded deities have very high Legend ratings, but some very famous mortals even without divine Ichor can have very low Legend ratings.
The godlike Reckoners/Manitou of Deadlands gain more power when they spread fear and belief in the supernatural.
The non-Abrahamic gods in In Nomine are called Ethereals, explained as being formed by humanity's imagination and empowered by their worship. Yves came up with the different Abrahamic religions in order to undercut their power, and Uriel opted to wipe them out directly before God yanked him up to the Higher Heavens to have a little chat with him about it. Of course, the Ethereals say that Yahweh/Jehovah/God was one of them and simply managed to gain enough worship to Retcon reality.
Eon, the highly detailed Swedish RPG, kinda works like this; gods generally don't die, but lack of worshippers can lead them to the brink of "starvation". An entity called "King Frost"; an amnesiac old man walking the frozen deserts of the northlands, is theorised to be a 'fallen god' clinging to life. It's worth to note that the gods can return when they get worshipped again though.
Over the Edge, here it's part of All Myths Are True, one character in a splatbook takes a drug that allows humans to commune with the gods. Hecate scolds him and tells him to go back to church and let her "sleep"
This one is Older Than Feudalism - in The Birds, the Greek gods lose power because the prayers they were offered couldn't reach them because of a great wall built in the sky. (Actually, it was not prayers that were intercepted - it was rather more physical smoke of animal sacrifices.) The gods did not immediately lose power - rather, they suffered from hunger, although they turned out to have some stockpiles of smoke and rationed the smoke. It was a plot point that not only Greek gods suffered - non-Greek gods were also starving and did not have stockpiled smoke. They accordingly threatened to attack Greek gods unless they made terms with Nephelokokkygia that would lift the blockade.
Physical God Mata Nui of BIONICLE fame would have died if the Matoran people had stopped doing their jobs. And this trope was applied with good reason — he was a Humongous Mecha, and the Matoran kept him functional by doing essential work inside him.
This ends up becoming a gameplay mechanic and a key plot point in Neptunia. Goddess party members gain stat points when the shares of their homelands increases, usually by completing dungeons there.
In the first game, Arfoire, the villain, spends most of the game spreading rumors of a fake overlord with monster attacks and heretics, using the fear and belief of the people to gain power. It's how she kept reviving and getting stronger each time.
In the second game, Arfoire's goons are deliberately increasing Arfoire's shares (by taking them from the goddesses) in order to revive Arfoire.
At least thrice in the third game, but for separate reasons. The first time it happens, Eden, a new nation born from the Seven Sages (or what's left of them), ends up sapping the shares as the new console on the market, the TurboGrafx-16. The new console (Yellow Heart) holds well, but its price threshold and the eventual reveal about who she really is marks the end of its short life. The second time, although it takes place in the past but is explained near the end, the previous nation's CPU, Rei Ryghts, was the leader of Tari. She controlled the populace through fear and greed, but she didn't know her power was fueled by the people, so when that happened, the people revolted and she became extremely weak. In retaliation, she decided to destroy the entire nation outright. The third is when Future Rei manipulates the populace to only believe in her and weaken every other nation, effectively destroying the balance of the dimension's shares and threatening to destory an entire dimension with her newfound power.
Alundra: The villagers of Inoa pray to Melzas, who is (unknown to said villagers) actually evil. Even better (or worse,) Melzas knows he gets his powers from prayer, and thus perpetuates a vicious cycle of secretly inflicting horrible nightmares on the people of Inoa to keep them in fear so that they keep praying to him. Also Nirude, a giant god, lives off the prayer of midgets.
The Elder Scrolls: The more people worship a given deity, demigod, or what-have-you, the more powerful they become. Greater gods like the Nine Divines and Daedra Princes can survive without it, but will be seriously weakened until they get more followers. Lesser gods can be outright killed by lack of worship. The reason it's easier for greater gods is because they personify widely-known abstracts, so even if all their followers in one culture are purged, they have another culture to pick up the slack.
Some EU and even in game dialogue hints/explicitly states that after the events of Morrowind the leader of the indigenous Tribunal religion, Vivec, disappears without a trace. And the large floating rock used as a religious prison and held aloft by "the love of the people for [Vivec]" smashes into Vvardenfel, causing massive destruction across the entire island. Did you forget that you're the one who revealed his religion as a sham?
According to Word of God, this is a motive factor in Skyrim, where the Thalmor, a faction of elven supremacists, have forced the empire to ban the worship of Talos, leading to the Stormcloak rebellion. The stated reason for this is that the Thalmor refuse to accept that a human could achieve godhood, although it is suggested that destroying Talos by depriving him of worship is one stage in the Thalmor's grand plan to destroy Mundus and Ascend to a Higher Plane of Existence. It should be noted that Talos isn't a God in quite the same way as the others, and in some sense has surpassed the Divines and Princes themselves. It is impossible to be sure if he even needs prayer, now, particularly since even as an "ordinary" human he managed to create a Dragon-break strong enough to (have) conquer(ed) an entire continent.
In Oblivion, if the Champion of Cyrodiil choses to do the Daedric quest for Sheogorath after becoming the new Sheogorath at the end of Shivering Isles, their servant questions why they just prayed to themself... only to then reconsider that as the Mad God, that sort of lunacy is rather appropriate.
Black & White's gameplay is essentially built on this trope, with your amount of followers determining your power, and much of gameplay being based around converting or looking after villages and villagers. Gods with no followers vanish in a Puff of Logic, which is how you win scenarios.
Power-ups in Ōkami come from the praise you get for performing miracles. And at the end, Ammy gets an Eleventh Hour Superpower through people praying directly to her. Purely cosmetic, though. Overall, this trope seems to be one of the game's underlying themes, as it's mentioned quite early on how people's faith in the divine has dwindled.
In Age of Mythology, the player literally generates favour for their gods to produce miracles. Greeks pray at temples, Egyptians build monuments, Norse go to war, and Altanteans control town centers to generate favour.
Seven Kingdoms had temples where you'd sent people to pray to your nations "Greater Being" (based on a god of the respective mythology). In this case, you'd could either summon the god himself (some are fighters, some have special abilities) or trigger a random miracle.
Subverted by Ladon the dragon god, who's a bit grumpy that nobody believes in him anymore but nonetheless continues to exist.
The more worshippers you have in Populous, the more powerful miracles you can perform.
In the first two games, only settled worshippers benefit you in that way, by the strength of the settlement. Giving you the choice between producing a lot of worshippers or personal power and tougher worshippers.
Touhou works like this (and Clap Your Hands If You Believe in general). This is most relevant in the 10th game, Mountain of Faith, where goddess Kanako Yasaka, faced with fading away due to modern Japan's waning faith in the divine, decides to relocate the Moriya Shrine to Gensokyo, where she ought to have an easier time finding worshipers. Unfortunately this muscles in on the local religious "authority," protagonist Reimu Hakurei, and Bullet Hell ensues. After this ends, Kanako stays around and attempts to gain faith other ways, treating the whole thing like a business venture.
Lampshaded in Blood Omen: Legacy of Kain when Kain remarks, "The act had taken on the feel of ritual. Isn't it strange how we must bribe our gods to stay?"
In Fate/stay night, the Heroic Spirits (not outright gods but at least a few levels of spiritualism above humans) mostly exist due to - and are partially sustained and empowered by - the belief they've inspired in humanity. Their strength appears based partly on their actual power and partly on pure Popularity Power. As Rin explains in the game prologue, even fictional characters count, what matters is the image created by the minds of the people. The game features two major explorations of this - Assassin is a nameless samurai called forth to play the role of Sasaki Kojiro, an opponent of Miyamoto Musashi, who is entirely fictional in the Nasuverse. In other words, the pure belief that humanity has in the existence of said hero is so strong that it allows him to exist, albeit through summoning a nameless spirit to take on his name and fill his role. On the flip side, Archer is a hero from the future; nobody knows of his existence and he therefore owes neither his existence nor any of his powers from belief, persisting as a Heroic Spirit only through the connection all Heroic Spirits have with the earth itself. Heracles, naturally, gets top billing either way you look at it. Gilgamesh (the very first Heroic Spirit) and King Arthur also rank highly, as does Iskander in Fate/Zero.
Some gods in the Nasuverse also experienced this. While some existed before there were beings who could believe in them, many Divines Spirits were created by the belief of humanity. As time passed and worship waned, they faded and became weaker Elementals. Gilgamesh was created by the gods of ancient Mesopotamia in a vain attempt to stop this from happening to them.
Subverted in the original for the SNES. While you gain levels as your population grows, it turns out that your powers are dependent on the number of people on the planet, not their faith. At one point, a Path of Inspiration turns a lot of people in one country against you, but it doesn't lower your levels. Additionally in the end your temples are empty because the people can stand on their own and no longer need you to handle their every need, but you don't fade away or anything.
In the sequel, one of the towns you need to save is initially closed off, because the townspeople there don't believe in you (and thus you can't read their minds).
During one sidequest in Baldur's Gate 2, you meet an avatar of a god with so little belief that he is fading away. Amaunator and a small village of followers were bound to immortally guard "the device" forever, over the years their faith has transformed to hatred and the avatar can barely even show himself, much less do anything.
In Dominions II the faith of people in various provinces is represented by a candle. This affects the knowledge you have on the province, the level at which you can affect it and, should you move it into the area, the hitpoints of your Pretender God.
The old gods reveal to the player in Ultima VIII; they are nearly powerless now that about everyone worships the four new gods instead.
Paper Mario. The star spirits in the first game gain power from the wishes of the denizens of Mushroom Kingdom. In the final boss fight, the young star spirit Twink gains enough power from Peach's wishes to beat up Bowser's sidekick and help Mario save the day.
Sierra's City Building Series cuts both ways. While gods need sacrifices or festivals almost constantly, ignoring them only makes them angry. Cue earthquakes, plagues, floods, failing crops... On the other hand, keeping them happy also brings benefices.
In Shin Megami Tensei, the gods, demons, and spirits feed on a substance called Magnetite or Magatsuhi - which is human belief and emotion and works as the setting's mana source. In Nocturne, when humanity was wiped out, demons had to abuse Artificial Humans to produce Magatsuhi to stay alive. In IV, one of the factions produces Red Pills, foodstuffs the demons find delectable. The Pills, naturally, are made of materials extracted from conditioned brain matter harvested from the faction's captured enemies, implying they're largely the same as Magnetite or Magatsuhi.
For as long as a single person believes in YHVH as his or her god, He will return, again and again. Unfortunately, it seems the Mega Ten universe works on the same principle as the Malazan example above-Humanity's own inner darkness and desire for a God that accurately represents them has horrifically twisted Him into a bitter, unsympathetic tyrant with nothing but contempt for humans.
Referred to in Sam & Max: Freelance Police, where Hell is conquered because too many goofy portrayals in media mean that nobody believes Beelzebub to be a threat any more and thus he is weakened, whereas the Soda Poppers are widely hated enough to have the power to challenge him.
The Neverwinter Nights 2expansionMask of the Betrayer is set in the Forgotten Realms. It shows just how far gods dependent on worship will go. They built the Wall of the Faithless, which punishes not sinners but non-believers. Being a atheist or a paying lip service to religion is the biggest of all sins against all the gods, and thus the good, evil, lawful, and chaotic gods all agreed that atheists shall be punished by ultimate torture and eventually the very destruction of their souls by having your soul slowly digested over thousands of years.
It should be noted that if you read the supplements, you'll find out that the current administrator only makes use of the Wall because the other gods forced him to. Also, this is a setting where the gods are very real and walked the earth in mortal form en masse less than twenty years ago (a period known as the Time of Troubles). On Toril, literally every atheist is a Flat Earth Atheist: ending up in the Wall for atheism is akin to starving to death because you don't believe food exists.
Not quite. The punishment exists not so much for atheism, which is only synonymous if this were monotheism, but for lack of worship and reverence to a particular deity. Long story short? If you either don't pick one specific deity who will save you from the Wall in exchange for your complete acceptance of what they are and stand for, or you worship Ao who exerts power over the others but does not accept worship of itself, or don't make a contract with a devil, who's imprisonment of your soul supersedes it, you're heading for the Wall.
WARNING! PLOT POINT AHEAD! The creator of the Spirit-Eater curse that drives the plot of MotB is the now-dead god Myrkul, who created it to ensure his immortality by abusing this principle: as long as there was a Spirit-Eater, there would be at least one person who feared and/or worshiped him, so he could never truly die. Then the game gives you the opportunity to finish him offwith the Spirit-Eater.
This is a plot point in Disgaea 4: A Promise Unforgotten. The Netherworld and Celestia need fear and love from humans to maintain their power, but it's become difficult for demons to plant fear in humans since humans have become so corrupt that they now fear themselves more than demons. As a result, this means they no longer have to pray to angels for protection and guidance.
Though hatred sustains Hazama/Terumi's existence, thus making it necessary for him to be the worst kind of Jerkass possible in order to stay alive, he is still as far from sympathetic as one can get. He has no shades of I Did What I Had to Do, and has even openly admitted that he loves ruining other people's lives for the sheer hell of it.
Inverted in Sword of the Stars II with the Suul'ka. They don't need prayer from their Zuul underlings/worshippers. The Zuul, on the other hand, need to give that prayer if they want their "gods" to help. Given their shift from Difficult but AwesomeCrutch Character to Magikarp Power, this is a vital end-goal for them now. So Worshippers Need To Give Prayer Badly then.
In Injustice: Gods Among Us, Ares reveals that Superman's One World order had eliminated most conflict, leaving the God of War far weaker. In the game's tie-in comic, Wonder Woman suggests Ares become the god of something else in order to regain his powers, then hilariously calls him, "Ares, God of Ponies". In the game proper, Ares decides to help the heroes, explaining that their struggle against the Regime is empowering him in the short-term, but if the bad guys win, conflict will drop completely.
In Dungeon Crawl the gods are powered by worship. This doesn't come up very much, because they have plenty of worshipers. All of them except Jiyva the Shapeless, god of slimes. There's only one slime smart enough to worship it and if you kill it, unless you yourself are for some reason a follower of Jiyva, the god ceases to exist.
In Final Fantasy XIV: A Realm Reborn, the Primals are brought forth from the aetheric flow by the worship of their followers. Unfortunately for said followers, Primals take a very proactive role in ensuring their continued worship by "tempering" them into mind-controlled slaves who seek to gather more people to turn into brainwashed worshippers. The player turns out to be one of a handful of people immune to tempering. This is a good thing, as your first encounter with a Primal is as part of a group of prisoners brought before Ifrit to become his new servants.
Like the Populous example above Peter Molyneux is at it again with Godus where the number of followers affects the type of spells you can use.
Tears to Tiara 2: The reason Tart at first could not cast even a single heal spell and is no different from a teenage girl. Her people are forced by the Holy Empire to worship Watos, and her temples are torn down to build churches. Only by Hamil's desperate pleas for guidance was she even able to take form. Part of her powers come back to her on the Canaanites' battle cry of Ashtarte, and prevents both of them from being burnt alive.
In Asura's Wrath, humanity prays to provide the Seven Deities with Mantra, which is used as a power source for various weapons in their fight against the Gohma. Unfortunately, the Deities later learn how to take Mantra by force...
A variation in The Wolf Among Us: Fables are classic fairy tale characters forced into the real world. If their fairy tale is popular among "mundies", then that belief makes the Fable very resistant to physical injury and capable of healing very quickly. For example, Little Red Riding Hood is one of the most popular of all fairy tales, and hence the Big Bad Wolf can survive dozens of shotgun blasts at close range, and the Woodsman can survive taking his own axe to the back of his head. It is also suggested that killed Fables can be resurrected if enough people still know about their stories. The only way for a Fable to be permanently killed is if not enough people know about their story any more as is seemingly the fate of Faith and Georgie Porgie, or if the Fable is physically thrown down the Witching Well as is possibly the case with the Crooked Man.
In A Moment Of Peace the gods of the universe eat human emotions to survive, like baked cheer or gruel made of sorrow.
Played With to an epic extent in the (now completed) Indefensible Positions. Demons are sentient memes and it's implied that gods are simply demons with a lot of believers.
Fans! has the occasional god make an appearance. These gods usually claim they were conceived by Roman clergy, during nights with a little too much wine. These gods include the god of gaming, and the anti-cupid (who shoots you with a tommy-gun and takes away your devotion to another person).
The Order of the Stick universe in general employs this trope to explain any god not in the three original pantheons. In particular, Elan and some orcs are Banjoists, worshippers of Banjo the Clown, god of puppets. He doesn't have many followers, so his divine lightning is little more than a spark. One of the prequel books reveals that mortal character can ascend to godhood in this manner.
Since Elan was unwilling to leave Banjo (who is an actual puppet) with the orcs, he creates Banjo's twin brother and rival, Giggles the Clown, as the god of slapstick. The violence-loving orcs appreciate this, and immediately convert. So Banjo went back down to a single worshipper, but since they were defined as equally powerful rivals, that probably remains the case. The OotS-verse has established that being defined as a rival gives free XP to keep one side from being too weak for the role.
Elan once tried to get Banjo inducted into the Northern Pantheon, specifically to gain more worshippers. The local priest angrily rejected this idea, and Elan then decided Banjo was too good for their pantheon, unaware that Odin (who likes puppets) approved of the idea.
Similarly, several elves and one goblin became so revered after their deaths that they ascended to godhood
Movie snacks like Popcorn, Milk Dudes [sic], and Soda have apparently gained power "like unto tiny refreshing GODS!" from generations of popularity.
The Gods Of Arr Kelaan gain power from their followers, but mostly they provide their own (considerable) power.
Interestingly, the Abrahamic god is shown to be a concept created by a pantheon of minor gods in order to conserve the lessening magic in our world.
The Traveler Gods actually gain power from worshipers in a slightly sideways manner - worship itself doesn't grant the gods more power, but deceased souls that have an affinity for them (including those that were never worshipers, or never even heard of them) are drawn to their afterlives to seek enlightenment through exploration of some state of being (such as through learning, for Claremont the god of Science). As souls Ascend to a Higher Plane of Existence on achieving enlightenment, the gods gather power from the act of ascension. It's in their interests more to promote their portfolios rather than their faiths - Claremont would get more power from fostering a love of learning worldwide rather than creating an authoritarian church to enforce his dogma.
In Parallel Dementia, most nightmares (read: supernatural beings) gain power from belief. This also works for human, as demonstrated by a legendary assassin who faked her death who still gains power from people believing in her former name, Mistress of Blades.
A slight variant in Underling, in that they are powered by knowledge of them, even more so belief.
In Too Much Information some spirits can become Astrals by having enough worshipers. Losing those worshipers causes them to die.
In True Villains, there is a god of everything, but only five have any real power because they are believed in and worshiped.
Seen in the Whateley Universe with the New Olympians. After escaping imprisonment (by whom hasn't yet been revealed) into the modern world, the old gods of Olympus find themselves greatly weakened and without worshippers to draw power from, and end up having to take mortal hosts. Who in the present day form their own loose school clique at Whateley Academy...
It's also been mentioned in the canon background material that even simple spirits (basically considered randomly occurring self-motivated 'knots' of magical energy) may be able to evolve into 'gods' over time if given a source of worship to draw on.
Used in Adylheim: the less powerful gods require constant supplication and sacrifices to be made in their honour, whereas the more powerful ones merely use this as something of a divine power up. In return they're usually inclined to offer everything from providence to small miracles.
In the original Metamor Keep setting, where the gods are at the height of their power, they draw power from faith and actions done in their name. Though aside from the priesthood most worshipers only pray when they need something, and such favors often have a significantly higher cost.
While negotiating a system of catacombs as part of a ritual ordeal in ThunderCats, Lion-O discovers a beautiful, brightly-lit room full of treasures. A mysterious figure, clearly terrorized by his presence, attacks him but is too weak and decrepit to put up any resistance. After Lion-O assures him that he is not a thief, the creature introduces himself, explaining that millennia ago he was a much-renowned god, but that his power has withered to virtually nothing after enduring many centuries without having been worshipped. He goes on to explain that anyone can become a god, but few attempt it as without worshippers this is certain doom.
In the Care Bears episode "Share Bear Shines!", Princess Starglo explains that stars are powered by belief and wishes, but so few people believe in her or wishing on stars that she doesn't have much power left, which leads to her turning off all the stars in the sky (including the sun). By the end of the movie, she nearly fades away, but is saved by a burst of belief from the Care Bears. (One would imagine that seeing all the stars go out would be a powerful reason to believe, but there you go.)
In the Aaahh!!! Real Monsters episode "Where Have all the Monsters Gone?", it's revealed that monsters need the fear of humans to exist: if not enough humans are afraid of monsters, the monsters start disappearing bit by bit.