The Corinthians judged Paul, but listen to his response,
“But with me it is a very small thing that I should be judged by you or by a human court. In fact, I do not even judge myself. For I know of nothing against myself, yet I am not justified by this; but He who judges me is the Lord” (1 Corinthians 4:3-4).
What the Corinthians judged in Paul did not really matter. Paul could not be a good judge of himself either, because his self-bias found nothing against himself. However, that did not justify him.
Judging, hence, justification comes from the Lord.