The Epistles of Paul the Apostle to the Thessalonians were written by Paul from Corinth about A.D. 52. These two letters are the earliest writings of the New Testament. Paul tells these Christians what sort of persons they must be, and that they must do their duty every day and not stand idle, waiting for the Second Coming.

1 Thessalonians 4

4:17 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.