2 Corinthians 11:15-16

15So do not be surprised when Satan's servants do the same thing. They can also seem to be serving God. They may seem to be doing good things, but really what they do is bad. So God will punish them in the end.

16I say this again: nobody should think that I am a fool. But even if you do think that, still listen to me. Give me a chance to praise myself a little, as a fool would do.