2 Corinthians 13:2-3

I have said beforehand, and I do say beforehand, as when I was present the second time, so now, being absent, to them that have sinned heretofore, and to all the rest, that, if I come again, I will not spare; seeing that ye seek a proof of Christ that speaketh in me; who to you-ward is not weak, but is powerful in you