2 John 1:10

If any one comes to you, and brings not this teaching, receive him not into your house, and do not wish him well:

Titus 3:10

A man that is a sectary, reject, after the first and second admonition,

Galatians 1:8-9

But though we, or an angel from heaven, preach to you any other gospel than that which we have preached, let him be ac cursed.

Romans 16:17-18

Now I beseech you, brethren, to mark those who make divisions and cause offenses in opposition to the teaching which you have learned, and avoid them.

but now I write to you, not to associate with any one professing to be a brother, if he is lewd or covetous, or an idolater, or a reviler, or a drunkard, or an extortioner: with such a one not even to eat.

2 Thessalonians 3:6

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