1 Thessalonians 4:15-17

For this we say unto you by the word of the Lord, that we that are alive, that are left unto the coming of the Lord, shall in no wise precede them that are fallen asleep. 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 that are alive, that are left, shall together with them be caught up in the clouds, to meet the Lord in the air: and so shall we ever be with the Lord.