Crisis of Faith

Where is my faith? Even deep down ... there is nothing but emptiness and darkness ... If there be God—please forgive me. When I try to raise my thoughts to Heaven, there is such convicting emptiness that those very thoughts return like sharp knives and hurt my very soul ... How painful is this unknown pain—I have no Faith. Repulsed, empty, no faith, no love, no zeal, ... What do I labor for? If there be no God, there can be no soul. If there be no soul then, Jesus, You also are not true.

—Mother Teresa

A character with a religious belief, whether it be fervent, cas ual, or never mentioned before or since, loses it and spends an episode as an unbeliever until learning a valuable lesson about faith. More Anviliciously, a Hollywood Atheist Long-Lost Uncle Aesop may be introduced, just to be enlightened and then never heard from again. Thanks to the Moral Guardians, the Reset Button will be in full effect - after all, God Is the Status Quo - although nowadays it's getting more common to see this used for genuine Character Development, whatever the outcome.

More common in American media, with some Values Dissonance for audiences who aren't used to the assumption that people are religious by default. The real Unfortunate Implications come from the idea that not believing in God (it's usually the Abrahamic capital-G "God") is a phase people go through, rather than a legitimate philosophy in its own right.

A more angry reaction may include Smite Me, O Mighty Smiter! or Rage Against the Heavens. The character will most likely become either a Hollywood Atheist, losing all will to live or respect for morality, or a Nay Theist, accepting that God exists but refusing to worship him.

When the conversion comes complete with a readjustment of the moral compass, see Heel Faith Turn and Faith Heel Turn.

Not to be confused with Have You Seen My God?, where the divinity in question really is MIA.

Examples of Crisis of Faith include:

Film

The protagonist of Priest spends practically the whole movie in a Crisis of Faith.
In Signs, Mel Gibson's character is a former Anglican priest who lost his faith when his wife died. The Twist Ending makes him reconsider.
The titular alien in PK and his exploration of Indian religiosity can be seen as this, capped off with his highly traumatic encounter with the fraudulent guru Taspavi.

Literature

Arthur C. Clarke's short story "The Star" is about a Jesuit priest who has a crisis of faith when he learns that the planet that had its morally good inhabitants killed by a nova was the star over Bethlehem.
- The short story isn't a full example, as it doesn't end with the priest getting his faith back. This was changed for the television adaptation; whether that's a case of Adaptation Correction or Adaptation Decay is a matter of personal opinion.
In Warrior Cats, the whole of ShadowClan stops believing in StarClan after a loner named Sol predicted a solar eclipse and StarClan weren't able to. ShadowClan's leader Blackstar had already been having some doubts because life had been harder since the Great Journey, so it didn't take much for Sol to convince him that StarClan was powerless. They did start believing again, though, after some StarClan cats - ShadowClan's last leader and medicine cat - spoke to Blackstar and his medicine cat.
Drives a lot of the plot in A Dirge for Prester John. John tries hard to be a good Christian king of a kingdom of, in his view, heathen monsters. In the frame story, Hiob's faith is also shaken by John's account of Pentexore.
In Who Cut the Cheese? by Stilton Jarlsberg, Hi urges patience until the cheese returns on grounds that the teeny people's predicament might be the Cheesegiver's test of loyalty. He's right.

Live-Action TV

While House himself gets a pass^[context?] for being a misanthropic Jerkass, a wayward priest patient finds his faith again after seeing the fantastic series of coincidences that line up to save his life.
In the Scrubs episode "My Own Personal Jesus", Turk loses his faith in a just God after a hopeless Christmas Eve in the emergency room, but regains it after he finds a missing pregnant woman by intuition and helps her give birth. (Interestingly, Turk is the only character in the episode who professes strong religious beliefs in the first place, and the other major characters seem to look down on him for this.)
In the Quantum Leap episode "Leap of Faith", Sam leaps into a priest, and Al is uncomfortable with the whole thing. He reveals that he left the church as a child, after prayer failed to save his father from dying of cancer, and swore never to have anything to do with God again. However, he resorts to praying to God again when it looks like Sam's life is in danger.
An episode of Dead Like Me included a drunken priest whose faith is restored by Daisy revealing herself to be a Reaper.
Combat Hospital explores this one pretty thoroughly through an army chaplain who undergoes a crisis of faith as she serves in Afghanistan and sees the brutality of war up close and personal.
This is an ongoing issue for Scully of The X-Files. She was raised as a devout Catholic and already had a few issues reconciling her work as a scientist with her faith. When she joins the X-Files and paranormal events and aliens get thrown in, she struggles to strike a balance.
An All in The Family episode has Edith undergo one of these after Mike and a family friend are mugged on Christmas Eve, with the friend subsequently dying. Ironically, it's Mike who convinces her to reconsider.

Oral Tradition, Myths and Legends

The Book of Job, the oldest book in The Bible, is probably the Trope Maker, being the origin of the "if your life sucks, God is testing your faith" Aesop.

Tabletop Games

In The Final Trumpet, an adventure for the In Nomine RPG, the Archangel of Faith himself actually reaches this point, risking Armageddon in the process. Depending on the actions of the player characters, he may come back stronger than ever, or Fall completely to become the Demon Prince of Fanaticism.

Western Animation

The Simpsons has had a couple. For example, in Homer The Heretic, Homer decides going to church is too much effort, and starts his own religion. Then his house catches fire, and he's rescued by Ned Flanders.
South Park:
- Kyle loses his belief in God after Cartman gets a million dollar inheritance and buys his own theme park, while Kyle gets diagnosed with hemorrhoids. His faith is restored when he sees Cartman lose all his money, which Stan interprets was a Xanatos Gambit by God to punish Cartman the whole time.
- Another episode has all the Catholics in South Park (which is pretty much everybody) declare themselves Hollywood Atheists due to the Pedophile Priest controversy. They wind up reverting back after Priest Maxi makes a televised speech to the church hierarchy about not letting unnecessary bureaucracy and corrupt rules get in the way of religion's core message.
Inverted in Justice League, "The Terror Beyond", with Hawkgirl questioning her own Naytheism. She's genuinely surprised to learn that Wonder Woman gets stronger by asking the gods for aid, and admits at the end that she doesn't understand why a teammate (who believed in an afterlife) was able to Go Out with a Smile. The episode ends with this subplot deliberately left hanging.
One episode of Daria has Quinn take a sudden interest in stories of angels, and she becomes convinced she has her own guardian angel when she happens to move just in time to avoid a dangerous accident. The problem is she comes to believe her angel will help her with everything, and becomes convinced that he's "abandoned" her when she embarrasses herself at a party. Daria puts aside her own feelings about the matter and helps Quinn decide she should only trust her angel for "big" issues.