Rapture
The tribulation (or the great tribulation) is supposed theory of a period of time somewhere around the rapture, where the Antichrist comes to power and controls the world. It is not entirely agreed among Christians whether the rapture occurs before (Pre-tribulation view), in the middle of (Pre-wrath view), or after the end of (Post-tribulation view) the tribulation, but most Christians seem to hold a Pre-tribulation view. Most Christians agree that the period lasts around seven years.