For the Lord himself shall descend from heaven with a shout, with the voice of the archangel, and with the trump of God: and the dead in Christ shall rise first: Then we which are alive and remain shall be caught up together with them in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord. - 1 Thessalonians 4:16-17
1 & 2 Thessalonians are the most important eschatological epistles in the New Testament. What is astonishing is that these two epistles remind their recipients of things which they were taught by Paul during the first few weeks that he was with them. Paul taught them all about the "end times" during their initial indoctrination into the faith: the Rapture, the Antichrist, the Great Tribulation, and the Second Coming!