|Recurring or debuting plot points in this episode:
- Mad skillz:
- Shirley sings a lot in this episode and Pierce accompanies her on the keyboard for one of those songs. At the end of the episode, Shirley sings a secularized version of "Silent Night".
- Winger Speech: Britta delivers one to Shirley.
- Previously: In the end tag, Troy mentions Abed's "special drink" which Abed described to Jeff in "Home Economics".
- PCness: Dean Pelton dresses up as a non-denominational "Mr. Winter" and shouts "Merry Happy".
- History lesson:
|Recurring or debuting characters in this episode:
- First appearance:
- Familiar face: The Greendale Human Being returns dressed as a reindeer and pulling Mr. Winter's sleigh with a bike.
|List of Running gags
|Recurring or debuting running gags in this episode:
- Attention students!: Dean Pelton makes an announcement about winter break, the Winter Wonderland display in the quad which has catalogs for next semester's classes, and the appearance of "Mr. Winter" later in the student lounge.
- Double entendre: Shirley says she is tired of the Dean shoving his P.C.ness (political correctness) down her throat. Troy and Pierce eventually notice that P.C. sounds like penis but miss the more obvious fellatio parallel.
- Gasp: Annie gasps when Jeff says he needs a 65 to pass Spanish.
- Gay, he's so gay!: Britta teases Jeff about the homosexual undertones in the fight he has with Mike.
- Nice outfit: The first of Dean Pelton's outfits as "Mr. Winter", the non-denominational representation of Christmas.
- NOOOOOO!: Annie screams this when she thinks Chang is about to tell Jeff that he failed Spanish 101.
- OK we get it, you're young!: After Pierce mentions Billy Joel, Troy mouths "Who's that?" to Annie who mouths back "I don't know".
- Thrown together: Jeff gets a paper ball thrown at him when he says he is agnostic.
- WWBJD?: Shirley hands out bracelets inscribed with the acronym and is upset when she finds out that the study group follow different faiths from hers. She also pleads with Jeff not to fight Mike and instead turn the other cheek in keeping with her beliefs.
- Fivehead: Mike Chilada calls Jeff "Forehead" multiple times.
Joel McHale discussed an incident that happened during filming of "Comparative Religion" in a 2014 interview he had with Aisha Tyler on her podcast "Girl on Guy". In the scene where his character Jeff was being trained by Pierce, Chevy Chase egged Joel to not pretend to throw a punch and actually hit the training mitt he was wearing. Although Joel refused to at first, eventually he claimed to have done just that which resulted in Chevy getting injured.
- “You're a funny man. Wanna hear something funny, funny man? Knock-knock. My fist up your balls.”— Mike
- “Who's there?”— Jeff
- “What religion are you, Jeff?”— Abed
- “I'm agnostic.”— Jeff
- [Everyone boos]
- “Agnostic. Lazy man's atheist.”— Pierce
- “Sup!”— Jeff
- “No it's a question.”— Troy
- “Sup?”— Jeff
- “Not a real question, a rhetorical one. You have the answer he does not.”— Troy
- “Then you look straight through his eyes, and deep into his soul.”— Troy
- “And then you move to Vermont.”— Britta
- “I am sick and tired of you saying that fighting is gay.”— Troy
- “She's got a point. You know, in boxing you fight for the purse and the belt.”— Abed
- “I've got to write a paper about that.”— Britta
- “Shirley, don't be mad.”— Jeff
- “I'm not mad; I'm disappointed.”— Shirley
- “That's "mom" for mad!”— Jeff
- “There's an old Buddhist saying in my vision group-”— Pierce
- “You are not a Buddhist, you are in a cult.”— Britta
- “Suck it, Nietzsche.”— Pierce