Romans 16:17

As we have said before, so I say again now, if any man is proclaiming to you a gospel contrary to what you received, let him be accursed!

Now we command you, brothers, in the name of our Lord Jesus Christ, that you keep away from every brother who walks in an unruly manner and not according to the tradition which they received from us.

As I exhorted you when going to Macedonia, remain on at Ephesus so that you may command certain ones not to teach a different doctrine,

Reject a factious man after a first and second warning,

If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting,