Railing: Forbidden
Source: Nav
1 Corinthians 5:11
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.
1 Timothy 6:4
he is conceited and understands nothing. Instead, he has an unhealthy interest in controversies and semantics, out of which come envy, strife, abusive talk, evil suspicions,
1 Peter 3:9
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.
2 Peter 2:11
Yet not even angels, though greater in strength and power, dare to bring such slanderous charges against them before the Lord.
Jude 1:9
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!”