- Author Tract: The movie Left Below:Thompson: It's the Rapture, Shauna, the Rapture! The virtuous have gone to Heaven, and the rest of us have been... Left Below! We were fools! And because we rejected God (tacitly accepting Satan), we must suffer through the Apocalypse.
Buddhist Monk: I thought all religions were a path to God; I was wrong!
Scientist: Why did I put my faith in science and technology?!
Homosexual: Oh, why did I choose to be gay?!
- The Cloud Cuckoolander Was Right: Homer was right about the Apocalypse happening.
- Shout-Out: For his haircut, Ralph Wiggum produces a photograph of Charlie Brown to show what he wants his hair to look like.
- Show Within a Show: Left Below, a parody of Left Behind.
- Status Quo Is God: God restores the Status Quo by chanting "Deus ex Machina".
- Take That: The Left Behind analogue is (accurately) depicted as an extended author tract with the subtlety of a sledgehammer.Homer: This movie will haunt me for the rest of my life, just like Cannonball Run 2!
- Title Drop: One of the characters in the movie "Left Below" comments that he and others were left below. Cue Homer wondering where he's heard that before.
- Ungrateful Bastard: After Homer's first calculations prove incorrect, everyone treats him like a pariah. This wouldn't be so bad, except Homer's initial prediction brought out the best in people like Moe. However, they don't look at the upside, nor do they consider Homer had their best interests at heart. It's made worse when Marge throws Homer's corrected calculation back in his face. As Homer drives to the Mesa again, he actually considers this trope.