There are many characters who strongly believe something. The Knight Templar and Well-Intentioned Extremist come to mind, but there are others. The thing is, what if they realize that they're wrong? This trope happens.
Break the Believer is what happens when a character who is a true believer in something realizes they were wrong. Now, given that these characters are often fanatical in this belief, it won't be as easy as changing their opinions. They have discovered that their core beliefs, the very heart of their worldview, are wrong. They are shattered, and their lives become meaningless. If they have a crusade, they give up on it. Sometimes they get better. Sometimes, they don't. Depends on the writer. The degree to which a character is impacted by Break the Believer depends on how much of a fanatic they are (or were). Characters who just feel strongly about something will not be as harmed as a character who is The Fundamentalist.
This sometimes is accompanied by a Heel Realization. In darker works, the character may be Driven to Suicide, which can be an absolute Tear Jerker. This is a Sister Trope to Break the Haughty and Break the Cutie. Happens fairly often to The Only Believer. Contrast HeelFaith Turn, where a character finds meaning in belief. Sometimes results in FaithHeel Turn, and can come on the heels of Not Quite the Right Thing. Super-Trope to Crisis of Faith. This trope is almost always Played for Drama.
This is often an Ending Trope, so be forewarned, you might encounter SPOILERS!
- Puella Magi Madoka Magica: The revelation that magic exists and sociopathic demon-like aliens rule the universe / keep it from dying specifically by torturing innocent people and using their suffering to reverse entropy, tends to drive most religious people insane, like Sakura's father, who pulled a Pater Familicide just upon learning that his increased church attendance was due to his daughter's magic. Most of the girls get driven to despair upon learning the Awful Truth as well which Kyubey deliberately does in order to cause them to turn into witches.
- Wanted: Jokeresque character Mr. Rictus was once a devout Christian. When he had a Near-Death Experience and saw nothing, he decided that life was meaningless and abandoned all moral guidelines.
- Chick Tracts: In a tract called "The Visitors," this happens to two Mormons when the Jack Chick-approved evangelicals show them that Mormonism is a big fat lie, but then they get saved. Yay.
- Another Chick Tract, and although it may seem like a parody of this trope, it's not. In the tract "Fairy Tales?" after learning a horrifying truth, a child (Harry Garner) goes on a killing spree, burning down his school and eventually becoming the FBI's most wanted fugitive who is then arrested, tried, executed, and sent to Hell. What was the truth so dreadful it drove this child to kill? The fact that Santa, the Tooth Fairy, and Easter Bunny aren't real.
- Garth Ennis' Just a Pilgrim ends with the title pilgrim (a pragmatic survivalist who's gotten through the end of the world thanks to his faith in God) losing it when he finds a race of mutant jellyfish that have possessed a young girl who's part of a colony trying to leave Earth. This causes a Rage Against the Heavens breakdown ending in a Heroic Sacrifice to let the colonists leave. Garth Ennis is a very vocal atheist.
- Zigzagged in the "Apocalypse" arc of Spawn, Granny Blake suffers this when the Rapture occurs and God, having formerly been incarnated as her grandson, takes a cruel delight in explaining that he is not a gentle, loving soul, and nor does he love humans. Indeed, he sees humans as nothing more than toys to play with and break as he sees fit. He then turns her into his brainwashed soldier and sends her out to slay demons and the humans his brother, Satan, picked to serve him. In the aftermath, although clearly traumatized, Granny Blake can be seen vehemently spitting denials, insisting that the "thing" she met was not God and that there has to be a "real" God, the God she believes in.
- Serenity: When Mal confronts the Operative with the results of the Alliance's attempt to create a peaceful Utopia, his entire worldview and self-justification are broken. Rather fitting, given what happened to Mal himself in the series.
- Dogma: During his long exile in Wisconsin, the fallen angel Loki has taken to breaking the faith of members of the clergy as a hobby to pass the time. When we're introduced to him he is using the example of the Walrus and the Carpenter to make a nun lose her faith.
- In Star Trek V: The Final Frontier, Sybok is devastated when he realizes that the God of Sha-Ka-Ree is a false god who manipulated him.
- The Count of Monte Cristo: After he escapes from prison, Edmond Dantes lives to avenge himself on his enemies, who framed and betrayed him. However, close to the end, he realizes that he is not Providence due to his schemes causing the death of an innocent and nearly causing Death by Despair in one of the people he'd sworn to protect, and has a major crisis of faith. But he does recover from his Heroic BSoD, give up his vengeful ways, and set off for an unknown destination with his lover Haydee.
- Zig-Zagged in Discworld with Reg Shoe, a zombie. At first, he's introduced as an annoying Zombie Advocate with some redeeming qualities. Once he joins the Watch, he at first mostly gets complaints from other undead, before finally mellowing out into a good copper. We get to see him when he was alive, and it turns out he was a desperately smug and naive idiot who truly thought the revolution would make things better for everyone, believing himself a righteous martyr fighting the good fight (when the People he fights for would give him a good clip on the ear if they caught him overturning trashcans and graffiting walls) and his brain reboots in the face of facts disproving his view. When he finally can't deny it anymore, he breaks down sobbing before going into Unstoppable Rage, dying and waking up as a zombie.
- The Gadfly: Twice.
- The protagonist, Arthur, is betrayed by the man he most adores, a Christian priest, thus causing him to become a hardcore atheist and condemn the church and all its teachings.
- Also seen in his mentor and priest, Montanelli, who sentences Arthur to death for attempting to help revolutionaries, despite Arthur being his son - figure and being given the chance to escape the prison by abandoning his hatred of religion. Arthur is ultimately executed, causing Montanelli to suffer a mental breakdown and publicly denounce Christianity.
- In the John Carter of Mars book Gods of Mars, Xodar, one of the Firstborn, is first introduced as a haughty, chauvinistic follower of the goddess Issus, but after falling out of favor with his people, he finally gets to meet Issus personally... and he finds out that she's really just a hideous, cruel old woman. This sends him into a Heroic BSoD from which John Carter has to rouse him. Afterwards, he becomes one of Carter's staunch allies.
- Les Misérables: Inspector Javert subscribes fully to the idea that all criminals are inherently evil, and that the law is completely good. However, when the criminal he has pursued for decades saves his life, he finally realizes his error and resolves the resulting moral dilemma by throwing himself into the Seine.
- George R. R. Martin's The Way Of Cross And Dragon ends with the protagonist, an inquisitor of the 30th century One True Catholic Interstellar Church, losing his faith thanks to the titular heresy making him realize that religion is just a fiction to keep the masses happy. And his superior doesn't care that he no longer believes and refuses to let him retire, he's too effective.
- Invoked and subverted in Silence by Shusaku Endo deals with a historical incident where Portuguese priests in 1600s Japan are forced, alongside other Japanese Christians, to apostatize by stepping on the fumie to symbolize their loss of faith. The main priest character is haunted by the "Silence of God" in the wake of all this suffering and the ineffectiveness of martyrdom in his contest. In the end, he apostatizes but when another apostate comes to him asking for sacraments, both of them realize that they still had faith even after the ritual, and the priest has a reverie where he realizes that by apostatizing out of compassion for other persecuted Christians, he was still acting in a manner befitting a Christian. As he reflects:
I, too, stood on the sacred image. For a moment this foot was on his face. It was on the face of the man who has been ever in my thoughts, on the face that was before me on the mountains, in my wanderings, in prison, on the best and most beautiful face that any man can ever know, on the face of him whom I have always longed to love. Even now that face is looking at me with eyes of pity from the plaque rubbed flat by many feet. 'Trample!' said those compassionate eyes. 'Trample! Your foot suffers in pain; it must suffer like all the feet that have stepped on this plaque. But that pain alone is enough. I understand your pain and your suffering. It is for that reason that I am here.
- In The Supernaturalist, Stefan, who is trying to avenge his mother by fighting Parasites, who he blames her death on. The way he was fighting the parasites was actually helping them reproduce, and making more of them. But wait! It gets worse! Turns out that Ellen Faustino, who he had seen as an ally was actually using him, is actually responsible for his mother's death, and the Parasites are actually good and helping people. Ouch.
- Protagonist Merlin Athrawes takes a certain guilty pleasure at being able to do this. Safehold is a human colony held in the grip of Medieval Stasis by a Path of Inspiration that has, over the centuries, also become a Corrupt Church. When confronting particularly vile clergymen, such as the man who organized an assassination attempt on his friends or the Inquisitor who supervised a massacre of civilians, he makes very sure they know that their church is a lie and the Archangels were mortals they would soon be joining in Hell. Since these condemnations come almost immediately after Merlin has One Man Armied his way through every last defense his victims have, he tends to be convincing.
- In the finale of "At the Sign of Triumph", Vicar and Grand Inquisitor Zhaspahr Clyntahn, the Big Bad of the series up to that point, has been arrested and is awaiting execution for his many crimes. The narration explains that Clyntahn didn't bother participating in his own trial, regarding it as a sideshow and arrogant in his belief that once he dies he would sit at his patron Archangel's right hand. Then Merlin and Nimue Chwaeriau visit him the night before his execution. They tell him his church is a lie, demonstrate the abilities they possess as Ridiculously Human Robots, then leave him with an hour or so of file footage showing the Archangels arguing with the Church's devil equivalent, Shan-wei, as she tries to convince them not to brainwash humanity. The experience shatters Clyntahn, leaving him a gibbering wreck as he's led to the gallows, able only to cry that he did everything he did because he thought the Holy Writ was true. Those not in on the secret simply believe he's gone mad in his last moments.
- In The Dresden Files fifteenth book Skin Game:
- Throughout the book, as Harry must work with the ancient villain Nicodemus Archleone for complicated reasons, he encounters the fanatics Nicodemus has raised since their births to believe him to be a powerful, unbeatable, immortal man and their hero. Harry is friendly with one named Squire Jordan, giving him a hot burger and crossing the line purposefully with a warning about it burning his tongue on itnote , and giving the kid some sage advice about the dangers of Nicodemus and the Coins they have aren't as cracked up as Nicodemus makes them out to be. Harry's goal is just to give these guys a chance to make a better choice. By the end of the book, in part from Harry's actions and in part when a good man in the right place at the right time, reforges the broken Sword of Faith into a blade of angelic light, complete with a low but resonating humming, that cuts through Nicodemus' sword and sends the man running, the newly minted Knight of the Cross stares down Jordan and other Squires still able to fight and breaks their wills and their faith in Nicodemus.
- This is averted with Michael's attempt to turn Nicodemus back to the side of the angels. After making a great sacrifice to reach where Nicodemus is, Michael tries to break Nicodemus' belief in his own greatness and his ability to lead the Fallen Angel that has been his partner for 2000 years. However, the man is so deep into his own lies, he refuses to break and continues his evil ways, starting with trying to kill Harry and Michael.
- Firefly: In the prologue scene from the pilot, during the battle of Serenity Valley, there's a blink-and-you'll-miss-it moment when Mal takes a cross on a pendant and kisses it for luck. Fast-forward a few years to after the final Independent surrender and he's now a staunch and rather bitter atheist.
- One episode of Father Ted has Father Dougal accidentally break a bishop's belief in Christ and Christianity just through being such a Cloud Cuckoolander and suckering him into non-sequitur conversations. By the end of the episode, the bishop is hitting the hippie trail in a VW bus with a bunch of stoners to find an alternative spirituality, although Dougal still has no idea what is going on.
- Within Temptation has a song called "The Truth Beneath The Rose," about a Christian fanatic seeing the error of their ways, and which strongly implies that this trope happens. Though because the fanatic continues to talk about forgiveness of sin and redeeming their soul, it arguably falls more along the lines of God Before Dogma.
- Warhammer 40,000
- Mammon, a backwater, near-dead planet in the Screaming Vortex, is populated by people with lunatic faith that the Emperor will one day return and create a golden age. Chaos forces that raid the planet for slaves take sadistic pleasure in informing the natives that the God-Emperor has been on life support for ten millennia, showing them just how little they matter. Another favored tactic is to make them watch one of the endless battles between their faction and the identical "heretic" faction and try to figure out which is which.
- One Space Marine Chapter Master with ties to the Inquisition prayed to the Emperor that they might be able to tell truth from lies. Unfortunately, Tzeentch heard his prayer, and now they could hear every lie across the Imperium, all the time (and since much of Imperial creed is contradictory or outright wrong, and the fact that its very basics were written by the Traitor Primarch Lorgar...). They fell to Chaos in record time.
- The Word Bearers Primarch Lorgar suffered this courtesy of the God Emperor himself. He was devoted to the Emperor and considered him a god, writing books arguing his divinity and converting many worlds through the power of his skills at orating his father's "godhood". Unfortunately for him, the Emperor didn't want to be considered a god, saw religion as dangerous and a limiting idea on humanity's mind, and wanted to outlaw religion to starve the Chaos Gods of power, and so the Emperor destroyed Monarchia, the crowning symbol of Lorgar's work, and then forcefully rebuked and humiliated him and his Legion. Unfortunately for the Emperor and the rest of the Imperium, that was all the Chaos Gods needed in order to push the broken Lorgar into their hands and begin the Horus Heresy...
- The Emperor tried to do this to the last christian priest on earth in the short story The Last Church by pointing out all the flaws of religion, and explaining His vision of the future. The priest gives the Emperor a vicious "The Reason You Suck" Speech, accusing the Emperor of being a hypocrite who wants to be worshipped as a god in everything but name.
- In the META-4 universe of Mutants & Masterminds, this was the origin of The Nihilist. As a devout Christian, when his family was attacked, he stepped forward, secure in his righteous might, was beaten within an inch of his life, was forced to watch his family be killed while he could do nothing, and subsequently expired believing nothing was true and came back as an undead revenant who seeks to spread his message that nothing matters.
- In Magic: The Gathering, on the plane of Amonkhet, the mortals are all devoted to their gods, and even the gods are devoted to the God-Pharaoh. Everyone spends their lives training to be worthy of being by his side in the afterlife when he finally returns. So, this happens to everyone when the prophecies are corrupted, the God-Pharaoh turns out to be Nicol Bolas, and three new gods show up to kill the five original ones.
- The Rooms of Renunciation in Unknown Armies are designed to bring this about by trapping the subject in the very worst of their beliefs. It's remarkably equal opportunity — a Christian and a communist who get sent there will both leave with their beliefs torn down.
- In Wicked, Elphaba, who, starting from "Defying Gravity," is fighting for what she thinks is right, realizes in "No Good Deed" that she has actually been wrong and evil, begins to go mad. Just look at this quote: "Let all Oz be agreed: I'm wicked through and through!" In "For Good", Elphaba continues to go down this road as she speaks to Glinda, but then she recovers.
- In Death of a Salesman, Willy Loman, who is thoroughly convinced that "personality always wins the day" discovers that this core belief was wrong. He is so stunned by this realization that he feels he can only give his life meaning by ending it. And that is not a spoiler, it's right there in the title!
- Planescape: Torment: In life, Vhailor was a particularly fanatical member of a faction known as the mercykillers, who operate under the belief in delivering absolute lethal justice to any and all lawbreakers. By the time of the game, his soul remains bound to his body solely as a result of his fanatical devotion to this goal. It's possible to convince him of the inherent meaninglessness of law, which causes him to instantly die as his belief in existing falters.
- Diablo III has Kormac, an actual member of a Templar Order who is wholly devoted to the combat of good against evil, going through a moral crisis when he learns that the order brainwashed him into believing he was a converted criminal when he was in fact innocent. This eventually leads him to confront the order itself in order to uphold its ideals. But when he learns that the order's corruption runs straight to the top, that the Grand Maester, the First of the Order, is complicit in the horror inflicted upon new initiates, and that he plans to do this to everyone in Westmarch and beyond, he decides that the order needs to end.
- Kiyoharu in Shin Megami Tensei IV is a scarred, insane man barely clinging to sanity by his staunch belief that God will return to save the humans left in the desolate timeline of Blasted Tokyo. His insanity's deep enough that he doesn't remember it was angels who tortured him into insanity and grievously aged him before his time. It takes an actual Avatar of God informing him that no, it's not come to save anybody, only to make sure all life is exterminated before the next Genesis starts, to shatter his spirit and send him into what's implied to be a death spiral.
- Dawn of War II: Captain Apollo Diomedes, captain of the Blood Ravens honor guard gets hit with this trope hard, as the reveal that Chapter Master Azariah Kyras is a heretic causes him to rethink all his orders (which usually involved He Knows Too Much). And since he's served more than four centuries, that's a lot of silencing he's had to do. However, when he is finally given irrefutable proof a decade after he was first told of it, it takes him only a few missions to recover from the Heroic BSoD and go after Kyras for good.
- Wings of Liberty: During the entire game, you get to see infuriatingly smug Strawman News Media newscaster Donny Vermillion applauding Emperor Mengsk's every move and insulting Raynor. When the Raiders upload Mengsk's message that proves he destroyed the planet Tarsonis by luring the Zerg there, Vermillion is seen staring into space saying "I had a brother on Tarsonis... I had a brother!" before cutting to commercial. That's the last time we see him, he gets replaced by Katy Lockwell who informs us Donny was last seen with nothing but socks, Emperor Mengsk's manifesto and a pound of peanut butter.
- Downplayed in Legacy Of The Void: One of Amon's promises to his Tal'darim followers was that they would become hybrid once he ascended. The massively powerful hybrid are lab-grown, not melded from Protoss, and once the First Ascendant Al'arak discovers this he works with Artanis to bring Amon down by taking away control of the faction (Tal'darim society being heavily based on Social Darwinism and Klingon Promotion, there wasn't much left to break).
- Al'arak's master got hit hard with this when he accidentally hacked his way into Amon's personal mindspace and realized Hybrids make for good fireworks to celebrate the end of the galaxy. He might have convinced Al'arak sooner if he hadn't flayed his own skin off in madness.
- Throughout RWBY, Qrow Branwen has shown Undying Loyalty to Ozpin, even when others express doubt or even criticize his more dubious decisions. This breaks epically in Volume 6, starting with the revelation that Ozpin hid the fact that the Relic of Knowledge (Which they spent the last Volume trying to obtain) can attract Grimm just as well as negative emotions, and didn't say anything until a Grimm attack was well underway on their public transport. When Ozpin is forced to admit that he never had a serious plan to defeat the Big Bad and save the world, Qrow snaps, lays Oz out with a punch, and declares that their meeting was the worst luck of his life. Unfortunately, this broken faith causes Qrow to sink into a depression and worse drinking habits.
- The Legend of Korra: One of the first anti-bending people we see is an obnoxious guy in a park praising Amon and trash-talking benders. Naturally, he's present at the moment Amon is forced to reveal that he's a waterbender.