Scully: Mulder, those people, even when they were alive mangled biblical prophecy to the extent that it's unrecognizable. The year 2000 is just their artificial deadline and besides, 2001 is actually the start of the new millennium.
Mulder: Nobody likes a math geek, Scully.
(After they kiss)
Mulder: Well, the world didn't end.
Scully: No, it didn't.