When Bart is expelled for an incident at a medieval-themed fair at school (even though this accident was caused by Groundskeeper Willie, who was mad he wasn't chosen to be a cooper), he's sent to a Catholic private school led by an Irish priest (voiced by guest star Creator/LiamNeeson) who shows Bart and Homer the fun side of the Catholic religion. Naturally, Ned, Marge, and Reverend Lovejoy (who are Protestant) don't agree.
* AdultsAreUseless: Just because the school hates Bart doesnít meanÖ no, letís face it, they hate HIM to the point it was easy just to expel and let Willie get away. The only few exception would have to be Father Sean.
* BrokenAesop: One would think Bart and Homer had converted to Satanism or Scientology based on the way Marge, Lovejoy, Ned, and the rest of the town treat them. The only negative aspects of Catholicism that are actually mentioned in the episode are the lack of meat on Fridays (which most Catholics only observe during Lent) and a subtle joke about Catholic priests doing inappropriate things with children. This, combined with the fact that characters of other religions, such as Krusty or Apu, rarely if ever get chastised for their beliefs, means that the message about Christians learning to be accepting of those of different religious branches is highly lessened, as the Catholics in this episode had [[InformedWrongness no real reason to be hated in the first place]].
* CassandraTruth: Practically nobody believes in Bart's pleas of innocence regarding the prank he was expelled for.
* CrisisOfFaith: The premise of the episode, similar to "Homer the Heretic" (season four episode where Homer creates his own religious beliefs and stays home from church) and "She of Little Faith" (season 13 episode where Lisa converts to Buddhism after the local church allows advertising).
* CelestialBureaucracy: A follow inhabitant of Protestant Heaven explains this to Marge.
* DistantFinale: After Bart convinces the Catholics and Protestants to get along, the episode ends on a fade to 1000 years later, where two armies are fighting over the words of "God's last prophet, Bart Simpson."
* DoubleStandard: Bart and Homer's conversion to Catholicism is met with hatred and disgust (especially from Marge), the town ostracizing Marge for their change of faith, and Marge, Lovejoy, and Ned ''kidnapping'' Bart in an attempt to get him to change back, while the worst Lisa got upon [[Recap/TheSimpsonsS13E6SheOfLittleFaith converting to Buddhism]] was Ned hiding his sons in a bunker and Marge and Lovejoy trying to use Christmas to win her back.
* DramaticGunCock: Parodied in the climactic MexicanStandoff when [[https://frinkiac.com/gif/S16E21/1191943/1195071/ all four get a closeup of pumping their guns]].
* DramaticIrony: Audience members can't help but feel sorry for Bart when he's getting flak from everyone for something they [the audience] know Willie was responsible for.
* EskimosArentReal: When Lisa mentions how she decided to convert to Buddhism, Father Sean thinks she's talking about an imaginary friend
* FluffyCloudHeaven: Marge's ImagineSpot.
* JerkassRealization: Bart once again, he calms everyone down when he explains that Catholics and Protestants are both Christians, which got both sides to agree.
* KarmaHoudini: Groundskeeper Willie didn't get punished for the stunt he pulled and let Bart take the blame.
* MundaneAfterlife: Protestant Heaven has cricket and badminton, while Catholic Heaven has a Mexican fiesta, Italian dinner, and Irish dancing.
* NotHelpingYourCase: Despite Bart's innocence, smugly insulting Skinner wasn't very smart on Bart's part, to say the least.
* NotMeThisTime: Bart tries to explain heís innocent and didnít do anything wrong despite having a reason to sabotage the fair, [[YouHaveToBelieveMe which itís true but seriously it's already explained]].
* TheScapegoat: Bart was forced to take the blame, despite the fact he had nothing to with the mayhem Willie did.
* StandingInTheHall: Bart is forced into this while at a private Catholic school.
* TooSoon, ScheduleSlip, and BannedEpisode: This episode wasn't supposed to be the season finale for season 16, but Pope John Paul II died around the time of its original airdate and FOX (not wanting to piss off any Catholic viewers), rescheduled the episode to air as a finale while the originally-intended finale ("The Girl Who Slept Too Little") was pushed to season 17.
* TwentyMinutesIntoTheFuture: Last part was set 1000 years in the future.
* WhatHappenedToTheMouse: It's never shown how Bart gets back into Springfield Elementary or if he is ever proven innocent of Willie's prank.