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

4:6 That no man go beyond and defraud his brother in any matter: because that the Lord is the avenger of all such, as we also have forewarned you and testified.