1 Thessalonians 4:4-6:

That every one of you should know how to possess his vessel in sanctification and honour;
Not in the lust of concupiscence, even as the Gentiles which know not God:
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.

See also:

Sickness as Chastening and Judgment in the New Testament