2 Thessalonians 3:2-3, 6

and that we may be delivered from unreasonable and wicked men: for all men have not faith. But the Lord is faithful, who shall stablish you, and keep you from evil.

Now we command you, brethren, in the name of our Lord Jesus Christ, that ye withdraw yourselves from every brother that walketh disorderly, and not after the tradition which he received of us.