2 John 1:10

If anyone comes to you, and brings not this teaching, receive him not into your house, and say not to him, "Greeting,"

Titus 3:10

A factious man, after a first and a second admonition, avoid;

Galatians 1:8-9

But even if we or an angel out of Heaven should proclaim a Gospel to you other than that which we delivered to you, let him be accursed!

Romans 16:17-18

Now I beseech you, brethren, to mark those who are causing the divisions and occasions of stumbling, contrary to the teaching which ye learned; and turn away from them.

1 Corinthians 5:11

but, as it is, I wrote not to keep company, if anyone, called a brother, be a fornicator, or covetous, or an idolator, or a reviler, or a drunkard, or an extortioner??ith such a one, not even to eat.

2 Thessalonians 3:6

Now we command you, brethren, in the name of our Lord Jesus Christ, to withdraw yourselves from every brother walking disorderly, and not according to the instruction which ye received from us.