The phenomenon in which a work of ScienceFiction or {{Fantasy}} has only one religion (TheChurch) in it; furthermore, there are never any factions of it, or different interpretations of its belief.

This is related to LawOfConservationOfDetail. The lack of other faiths doesn't particularly break WillingSuspensionOfDisbelief, so why bother? Having said that, it's inherently unrealistic; our planet has seven or ten major religions in the modern day alone ([[StartMyOwn some founded individually]] and [[MorePopularSpinoff others spun off from existing ones]]), and other religions [[TheMagicComesBack have come to prominence]] and [[GodsNeedPrayerBadly since died out]]. But no one ever questions this when it happens, making it either an AcceptableBreakFromReality or something too controversial to touch with a ten-foot pole. It is most justified in works where much more is known about the spiritual world than in RealLife, and there's lots of evidence to back it up to the point that not believing in this faith would make one a FlatEarthAtheist (though that still doesn't explain the lack of factions; there is no hair so fine that people won't try to split it).

Ignore OutgrownSuchSillySuperstitions.

This trope is more of a [[SortingAlgorithmOfTropes Sliding Scale]] than a straight trope, since there are numerous aversions and subversions. We'll go in order.

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!!Played Straight: One Religion, No Factions

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[[folder:Literature]]
* ''TheWheelOfTime'', arguably. See "subversions" below.
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[[folder:Video Games]]
* In ''VideoGame/TalesOfSymphonia'', two entire worlds share the same religion with only minor cosmetic differences. Justified by the BigBad having created and actively running both. Although the village of Mizuho has its own gods.
* ''VideoGame/DeadSpace'' has Unitology, which is specifically mentioned to be the only religion that has survived into the timeframe of the games. [[spoiler:It is mass low-level MindControl by the Markers, preparing humanity to be turned into Necromorphs.]] It seems to be primarily modeled after a [[ChurchOfHappyology certain controversial religious movement]] in the United States, though the writers have said it's based on religious cultism in general.
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!!Averted: More Than One Religion

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[[folder:Anime and Manga]]
* ''LightNovel/ZeroNoTsukaima'' played with this, in the fact that humans have one religion, based off on CrystalDragonJesus version of Christianity in the FantasyCounterpartCulture of Vatican, Romalia. However, it is not the ''only'' religion per se, as the [[OurElvesAreDifferent Elvens]] follow a different one. This becomes a plot point in the third season.
* ''LightNovel/ACertainMagicalIndex'' has just every religious denomination that's present in the real world in its world as well. They're all true, and each has its own magic.
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[[folder:Literature]]
* Most of the works by Creator/BrandonSanderson avert this trope, by virtue of the author's fascination with religion and divinity.
** ''Literature/{{Elantris}}'' includes Shu-Dereth and Shu-Korath, offshoots of the base faith Shu-Keseg in the past. All three religions believe in unity - the unity of the heart (compassion), the unity of purpose (political dominance), or the unity of the mind (meditative clarity). Completely separate is the worship of the [[PhysicalGod Elantrians]] themselves.
** The Lord Ruler of ''Literature/{{Mistborn}}'' '''wanted''' to achieve this, but was never quite able, mostly due to the efforts of the Keepers. After [[spoiler:the Lord Ruler is killed,]] the situation shatters completely, with people turning to various faiths, new and old, for support.
** ''Literature/{{Warbreaker}}'' continues the trend, with the conservative, stoic worshipers of Austre on one hand and the colorful worshippers of the [[PhysicalGod Returned]] on the other.
** Finally, the religions of Roshar in ''Literature/TheStormlightArchive'' are just as varied as the people. The dominant religion in the area we see is Vorinism, where the people worship the Almighty and train to help him to reconquer [[{{Heaven}} the Tranquiline Halls]], but when we encounter a number of slaves, we are introduced to many more religions.
* ''Literature/{{Discworld}}'', with its proliferation of {{Physical God}}s. In fact, some gods are actually several different gods at the same time; apparently all it takes to pull that off is a pseudonym and a wig.
* ''ASongOfIceAndFire'': Though its stated that there many gods worshipped in many parts of the world, the following five religions are most prominently featured and have had major impacts on the plot: the nameless, faceless [[NatureSpirit old gods]] that are worshipped in the North and beyond the Wall; the [[TheChurch Seven Faced God]], also called the new gods, in the rest of mainland Westeros; the [[WarGod Drowned God]] in the Iron Islands; [[CrystalDragonJesus R'hllor]], also called the Lord of Light, is popular in Essos but only has few followers in Westeros (House Baratheon of Dragonstone and the Brotherhood without Banners); the Faceless Men of Braavos worship the [[CrossoverCosmology Many-Faced God]], a god of death that all other gods are avatars of.
* ''HisDarkMaterials'', even though TheChurch gets all the attention
* ''Literature/{{Wicked}}'', at least in the original book
* In ''Literature/{{Orcs}}'', not only are there several religions (mainly a monotheist and a polytheist one), but they are very important in the plot.
* Ender's Saga where matters of ensuring freedom of religion are plot-significant at some point.
* In the LeftBehind series during the Tribulation, there's the pantheistic mishmash of all world religions called Enigma Babylon One World Faith as the official one-world religion, but there's also Christianity (as defined by the books' authors and the Tribulation Force characters), Judaism, and Islam (which in the book series ends up being a minority religion), which all become illegal to practice even when Enigma Babylon is replaced by the Luciferian-type state religion of Carpathianism around the midway point of the Tribulation. In the Millennial Kingdom, Christianity becomes the official one-world religion, though dissidents are permitted to practice the beliefs of the Other Light despite the fact that (1) it's totally in error when it comes to believing Satan is going to defeat God and Jesus by the end of the Millennium and (2) [[DeathsHourglass those who remain unbelievers in God and Jesus Christ by the time they reach 100 will instantly die and go to Hell]].
* The ''{{Belgariad}}'' has one for every culture. At the end of the series, however, it's stated that [[spoiler:Eriond]] will eventually be the one god of the world, while the other gods move on to start life on other planets.
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[[folder:Tabletop Games]]
* ''{{Exalted}}'': While the Immaculate Order would certainly love to be the OneTrueFaith, the plain fact of the matter is that human nature and the cosmology of the setting works against it. As it is, they only really have this status on the Blessed Isle, and only there because they ruthlessly suppress any hints of non-Immaculate leanings.
* ''{{BattleTech}}'': Most 20th-century human religions have survived into the 31st century just fine and the Catholic Church at least has even found itself sprouting a whole new branch -- New Avalon Catholicism --, if somewhat by accident. (A breakdown in communications during the fall of the Star League regarding a temporary transfer of Papal authority away from occupied Earth had something to do with it.)
* ''TabletopGame/{{Eberron}}'', contrary to the typical Dungeons and Dragons setting, has comparatively few {{Physical God}}s running around (and most of those are both [[GodOfEvil evil]] and [[SealedEvilInACan currently incarcerated]]), the end result being that there are a vast number of religions in the setting. Some of the biggies include the Sovereign Host (and the related Dark Six), the Church of the Silver Flame, the Blood of Vol, the various Druidic sects, the Undying Court, the Path of Light, the PathOfInspiration, and the dizzying array of [[{{Cult}} Cults of the Dragon Below]]. Furthermore, all of these (with the exception of the PathOfInspiration, which enforces conformity and is controlled by immortal spirits with the kind of pull to make that happen) have further subdivisions within themselves.
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[[folder:Video Games]]
* ''VideoGame/{{Xenogears}}'' features two distinct major religions, (very) briefly hints at a third in one scene. Most of the beliefs of the organized religions, however, seem to be based upon a similar set of concepts.
* ''VideoGame/WorldOfWarcraft'' has multiple religious faiths, many of which are diverse from one another.
** In the Alliance, the humans, along with the dwarves and the draenei, practice a CrystalDragonJesus religion known as the Holy Light. The exceptions are the night elves, who worship a moon goddess known as Elune, possibly the Gilnean worgen, former humans who were brought to the Alliance by night elves (though their religious practices are almost unknown), and the gnomes, who have for the most part [[OutgrownSuchSillySuperstitions completely forgone religion in favor of science]].
*** It's noted in the tabletop roleplaying game that Elune is the only true actual deity in the game world, though that sounds like Night Elven propaganda to me.
*** It should be stated that the Holy Light is non-theistic (that is, it has no godhead) and allows for some degree of syncretism.
*** That said, earlier games make references to a more theistic bent, and references to a deity by worshippers of the Holy Light have been seen within World of Warcraft. Given the amount of turmoil that has taken place over the course of the games, it's entirely likely that the Church has undergone theological, philosophical and metaphysical developments.
** The Horde is split up for the most part. Orcs, as a whole, have a shamanistic heritage. Almost all trolls worship their multiple Loa spirit gods. The tauren worship their tribal deity known as the Earthmother. Forsaken undead have some sort of religion involving the shadow, themselves and the light(to a lesser extent). Blood elves follow the Holy Light. Its unknown what goblins worship but they can be priests.
** The Pandaren (both those on the Wandering Isle and on Pandaria) worship the August Celestials, four [[PhysicalGod Physical Gods]] based on the Four Symbols of Chinese mythology and astrology: Yu'lon the Jade Serpent representing the Azure Dragon, Chi-Ji the Red Crane representing the Vermilion Bird, Xuen the White Tiger representing the White Tiger, and Niuzao the Black Ox representing the Black Turtle.
** In addition, there are many other races that worship other deities: members of the [[ReligionOfEvil Cult of the Damned]] worship the [[BigBad Lich King]], many corrupted followers of the [[EldritchAbomination Old Gods]] exist, and there are many others.
* ''VideoGame/BreathOfFireII'', which sports the benevolent [[GodsHandsAreTied but mostly impotent]] Dragon God, the minor earth deity Namanda and the [[spoiler: [[GodIsEvil villainous]]]] [[CrystalDragonJesus Church of St. Eva]].
** Repeated in ''VideoGame/BreathOfFireIII'', with the God of the Urkans [[spoiler: (actually the Goddess Myria)]] and the Dragon God Ladon, who still has a few shrines as the "god of travelers" and serves as a Master.
* ''VideoGame/TheElderScrollsIIIMorrowind'' has the Imperial Cult, the Dunmer Tribunal, the native Ashlander religion, and the Dagoth Ur ReligionOfEvil.
** However, every culture in the game has basically the same creation myth. [[TheRashomon They just interpret it differently]].
** The Ordinators random bark of "Three gods, one true faith" has nothing to do with this trope.
** In other games, it's somewhat closer to Single Religions With Internal Factions -- the Imperial Cult's counterpart(s) is dominant (though there are other cults around -- some important to the plot -- and even more supposed to be around according to the lore even if they're missing from the games themselves), but there is a greater separation between followers of the individual gods of the Nine/Eight.
* ''VideoGame/VagrantStory'', with two
* ''VideoGame/LaPucelle'', technically: although the story centers on members of the eponymous church, there is another one who doubles as its theological rival, enemy and ChurchOfEvil.
* ''VideoGame/ArcRiseFantasia'' has three, although two (North and South Noireism) are kind of variations of each other.
* ''VideoGame/FinalFantasyX2'', where the former Yevonites have divided into the Youth League and New Yevon. The major bone of contention is the speed at which technology should be incorporated into daily life.
* ''Franchise/MassEffect'' takes place in the future, where humanity has not OutgrownSuchSillySuperstitions--the main religions of today still exist in the future, albeit at a lesser extent. (Most notably, party member Ashley is religious; while she never states ''what'' religion specifically she belongs to, it's generally assumed that she's Christian.) The discovery of Prothean ruins on Mars led to a few new human religions starting up. The alien species also have some diversity among their religions; the asari have both monotheistic Goddess (Athame) worship and a pantheistic religion called "siari". While the latter is more widespread, many asari still invoke the Goddess in casual conversation ([[OhMyGods By the Goddess!]]), similar to how atheists will say "oh my God" despite obviously not believing in Him. The drell have a traditional polytheistic religion, but the Thane notes that many young drell are turning away from it, and the Codex says that siari is becoming popular among the drell. Aliens are also adopting alien religions; the codex notes that Confucianism and Zen Buddhism are fairly popular among the turians, and a Cerberus Daily News story mentions businesses which provide dextro-amino kosher food for turians and quarians who have converted to Judaism.
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[[folder:Webcomics]]
* ''Webcomic/GetMedieval'', with both earthly religions and alien ones.
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[[folder:Real Life]]
* But of course. Also, nearly every faith is heavily fragmented into several different sects.
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!!Subverted: Single Religions With Internal Factions

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[[folder:Film]]
* ''StarWars'' (Jedi vs. Sith at the very least. The ExpandedUniverse features enough "alternative" religions to make the franchise an aversion, but we're ignoring those for the moment.)
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[[folder:Literature]]
* ''LordOfTheRings'', in which certain cultures (or subcultures) place more emphasis on their favorite members of the pantheon.
* Omnianism in ''Literature/{{Discworld}}'', going through endless schisms after the last prophet, Brutha in ''Small Gods''
* LoisMcMasterBujold's Literature/{{Chalion}} universe has two closely related religions who are bitter rivals, since they disagree about whether one of the five gods is, or isn't, TheDevil.
* David Weber's Literature/{{Safehold}} series is the story of one world's transition from a single monolithic religion to a deeply divided global religion - but it's still the ''same'' religion, just divided. The second and third novels in the series are called ''By Schism Rent Asunder'' and ''By Heresies Distressed'', which are a fairly accurate description of the fate of the Church of God Awaiting.
** The reason for the single religion is that it was achieved artificially through massive brain washing and by nuking any opposition from orbit. We do not know what the religious makeup of the original colonists was. Other religions might have popped up over the centuries but they would have been mercilessly wiped out by the Church.
* ''TheWheelOfTime'', like ''StarWars'', has one single monolithic belief system for the whole world - but it's dualistic, and the darker side has a few adherents here and there, and they're the antagonists. Well, the main antagonists. So that darker side might be considered a schismatic completely separate religion or a part of the same religion with different ways of observing it.
** As typical of Robert Jordan, every side also has different factions: for example, the Children of Light and the Aes Sedai both worship the Light and the Creator, but have a very different view of the One Power... Masema's followers also behave like a fanatical cult, putting Rand on the same level as the Creator.
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[[folder:Live-Action TV]]
* ''Series/DoctorWho'': In the future the army (human army that is) is run by the [[ChurchMilitant Church]] and among the Clerics there are mentions of both Anglican troops and of a Papal mainframe.
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[[folder:Tabletop Games]]
* ''DungeonsAndDragons''
* ''TabletopGame/{{Warhammer 40000}}'' has enough cults of the God Emperor that almost everyone is, indeed, a heretic.
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[[folder:Western Animation]]
* ''WesternAnimation/SouthPark'' had a two-parter set in the future where everyone has become an atheist. However, the atheists have split into many factions, fighting wars just as bloody as the religious wars of the past, over [[spoiler:what their name should be]].
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!!Played ''Both Ways''

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[[folder:Comic Books]]
* ''ComicBook/{{Artesia}}'' has multiple religions (the Old Religion of Yhera, the faith of the Divine King, and the mystery cults, among others), but they all fit into the same cosmology, many gods are worshipped in both religions, and the Phoenix Court of the Empire worships the Divine King but also pays respect to the gods of the Old Religion.
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[[folder:Literature]]
* ''Literature/HonorHarrington''
** Let's see, we've got the formerly SpaceAmish Church of Humanity Unchained, with its own internal factions, and its extremist splinter The Faithful, the Methodist-descended Third Stellars(which has practically every congregation (Or even every person) being their own faction), along with a 2nd Reformation Catholic Church, a new Judaism faction, and passing mentions of most other current major religions.
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[[folder:Live Action TV]]
* ''Franchise/StarTrek'', which features religious PlanetOfHats (Bajor), OutgrownSuchSillySuperstitions (while Roddenberry was alive) and religious proliferacy (after he'd passed on)
* ''Series/BabylonFive'': In the episode "The Parliment of Dreams" during a cultural exchange week each of the alien races put on some kind of demonstration of their religion. Every alien species only has one religion, but what will the Earth do? Finally it's Earth's turn.
-->'''Cmdr. Sinclair:''' ''shaking hands or bowing or giving the appropriate gesture'' This is Mr. Harris. He's an atheist. Father Cresanti, a Roman Catholic. Mr. Hayakawa, a Zen Buddhist. Mr. Rashid, a Moslem. Mr. Rosenthal, an Orthodox Jew. Running Elk, of the Oglala Sioux faith. Father Papapoulous, a Greek Orthodox. Ogigi-ko, of the Ebo tribe. Machukiak, y Yupik Eskimo. Sawa, of the Jivaro tribe. Isnakuma, a Bantu. Ms. Chang, a Taoist. Mr. Blacksmith, an aborigine. Ms. Yamamoto, a Shinto. Ms. Naijo, a Maori. Mr. Gold, a Hindu. Ms.... ''FadeToBlack''
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[[folder:Video Games]]
* ''Franchise/DragonAge'': more than one religion overall, but you only get one religion per race - there is no sense that any particular person could ever be a different religion from the one they are. The human religion, that of The Maker and the Prophet Andraste has some subdivisions, but these are clearly marked as 'real religion' and 'evil cult' so don't really represent religious diversity. The narrative itself (and the Warden, if you choose) can be read as having a subtle athiestic bias.
** Notably averted in Orzammar, where you find a dwarf cleric of Andraste who is genuinely good; should you choose to help him, you see ''why'' there's only one religion per race.
** There's also a subversion that gets a bit more attention in ''VideoGame/DragonAgeII'', where the Tevinter Imperium has its own schismatic Chantry that's under the control of the mages, rather than the other way around. Fenris calls it a scam to keep [[TheMagocracy the magisters]] in power, but we don't actually see the Black Divine or any of his people.
** Also, if you read the Codex, the reason there's only two versions of the Maker's worship is because the Chantry takes it ''very seriously'', aggressively wiping out variations of the faith. Kind of like the Catholic Church used to, only with more success. It's even part of the religion that the Chant ''must'' be recited ''perfectly'', with no variations. However, despite all of this, the occasional underground offshoot manages to thrive.
** Likewise, it's mentioned that when the Chantry decided to lead an Exalted March against the Dales, the "Canticle of Shartan" was stripped from the Chant of Light, [[OrwellianEditor removing all reference]] to the ''Dalish'' General of Andraste's army.
** It's interesting to note that, apparently as a result of being raised on the surface by exiled nobles from Orzammar, Varric Tethras is ostensibly non-religious, but frequently will invoke both the Dwarven Ancestors ''and'' Andraste's name.
** Hawke also appears to show acceptance of multiple, diverse faiths. Despite being nominally Andrastian, Hawke nonetheless aids Merrill in performing several Dalish rituals, in ''Legacy'' offers a Dwarven prayer after recovering the body of Varric's ancestor in the Deep Roads, works with the Qunari on numerous occasions and in ''Mark of the Assassin'', while also mentioning offhand that their family was one of the few that the Chasind Wilders chose to trade with in Lothering. A Snarky!Hawke gives a few hints that s/he is actually more of a NayTheist.
** While there's one ''main'' religion per race, there are some minority faiths and a few converts. In addition to the Andrastian dwarf mentioned above, the Chasind and Avvar barbarians are human polytheists, and there are a fair number of converts to the Qunari faith who are human or (especially) elven. Many of the city elves are Andrastian, though they retain some traditions of elven polytheism (such as the vhenadahl, or sacred tree). The Rivaini are pantheists who believe in a Natural Order (and also have a number of Qunari converts).
* In "Franchise/TheLegendOfZelda", the Triforce seems to be used universally and everyone seems to adhere to the same legends, yet each race is mainly seen worshipping deities separate from the Golden Goddesses - usually protector spirits like Jabu-Jabu or Valoo, but other ones as well, like the Ocean King or Hylia or the Desert Colossus. It's possible these all form a unified pantheon hierarchy, but that's never been made explicit.
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