Second Epistle to the Thessalonians
The letter then tells the Thessalonian church to stand firm in their faith, and to "keep away from every brother who leads an unruly(evil) life and not according to the tradition which you received from us... do not associate (stay) with him, so that he will be put to shame. Yet do not regard him as an enemy, but admonish him as a brother" (Chapter 3, verses 6,7, 14 and 15).