If the offended speaks to the offender and the offender refuses to admit his fault, go ahead and speak to a common brother of you two or a friend of your offender.
If he still refuses, speak to a spiritual leader you both share or just his. If after his spiritual head speaks to him and he still refuses to admit his fault and apologize, what else should you do?
Mat 18:17: And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, LET HIM BE UNTO THEE AS AN HEATHEN MAN AND A PUBLICAN.
If after all your efforts to get your brother to apologize for what he has done against you, to assist you to forgive him completely and restore the relationship between you both; he still refuses to admit his offense; Scriptures commands that at this point you treat him as you would an unbeliever. He is not your brother, but most likely not regenerated.
Thus, how should you treat an unbeliever who offends you? If an unbeliever offends you, God does not expect you to be surprised. A driver insults you, a bus conductor demeans you, your unbeliever colleague made fun of you, your boss ridiculed you, or whoever the unbeliever could be. As long as your offender is an unbeliever, GOD DOES NOT EXPECT YOU TO BE OFFENDED AT ALL. You should not be surprised that an unbeliever does something wrong. You should be surprised if they do good. Because they are of their father the devil and his lust they will do.
It is regrettable the way some Christians descend so low to exchanging words with unbelievers, fussing, or getting moody and angry over what the child of the devil does to them. Have you been so taught Christ?
It’s like a man exchanging words with a madman who insulted him. It only means though this sane man is not yet mad, he is soon going to be. Selah!
Hence if your so called “brother” comes to that level; just continue to love him, pray for him, and if necessary, share the good news with him all over again. He may not be your brother.
I refuse to fuss over what an unbeliever does to me. I can forgive. I choose to forgive in Jesus Name.