Railing: Forbidden

But now I am writing you not to associate with anyone who claims to be a brother but is sexually immoral or greedy, an idolater or a verbal abuser, a drunkard or a swindler. With such a man do not even eat.

…he is conceited and understands nothing. Instead, he has an unhealthy interest in controversies and disputes about words, out of which come envy, strife, abusive talk, evil suspicions,

Do not repay evil with evil or insult with insult, but with blessing, because to this you were called so that you may inherit a blessing.

Yet not even angels, though greater in strength and power, dare to bring such slanderous charges against them before the Lord.

But even the archangel Michael, when he disputed with the devil over the body of Moses, did not presume to bring a slanderous charge against him, but said, “The Lord rebuke you!”