2 Corinthians 11:4, 12-15

For if he that cometh preacheth another Jesus, whom we did not preach, or if ye receive a different spirit, which ye did not receive, or a different gospel, which ye did not accept, ye do well to bear with him.

But what I do, that I will do, that I may cut off occasion from them that desire an occasion; that wherein they glory, they may be found even as we. For such men are false apostles, deceitful workers, fashioning themselves into apostles of Christ. And no marvel; for even Satan fashioneth himself into an angel of light. It is no great thing therefore if his ministers also fashion themselves as ministers of righteousness; whose end shall be according to their works.