James 4:11-12

11My Christian friends, do not say bad things against each other. If you speak against another believer, you are really speaking against God's Law. If you judge another believer, then you are judging the law too. When you do that, you are not obeying the Law. You are giving yourself authority to decide what the Law says.

12God is the one who gave his Law to people. Only he has the authority to judge whether people have done what is right. Only he can decide to save people or to destroy them. So you must not judge your friends. You do not have that authority.