Therefore if thou bring thy gift to the altar, and there rememberest that thy brother hath ought against thee; Leave there thy gift before the altar, and go thy way; first be reconciled to thy brother, and then come and offer thy gift. -Matthew 5: 23, 24

A quarrelsome man when he is in a quarrel with another rather takes pleasure in it; he does not mind how many hate him, or how many he hates; his religion is quite consistent with the worst temper; he can say his prayers, or he can offer his gifts to his God, and yet be as malicious as he likes; but with the Christian it is not so, and must not be so. We are to bear a great deal of wrong before we make any reply whatever, and when we do give an answer, we must, if we would be like our Master, give a gentle one. Heaping coals of fire upon the head of our enemy by returning abundant kindness is the right revenge for a Christian, and all other revenge is denied to him. He is not to stand upon his rights; he is rather to say, “I know it is my right, but I will yield it sooner than I will contend; I know this man does me an injustice, but I will bear it sooner than my temper shall be ruffled, or my spirit shall be defiled, by a thought of evil.” “Oh,” saith one, “this is a hard measure.” Do you think it so? Are you a Christian then? for while in my soul I feel it is difficult, my heart feels I desire to do it, and I love it, and aspire after it; and I think every real Christian, though by reason of infirmity he often breaks this blessed rule, yet sees the beauty of it, and does not think it hard. Nay, rather the hard point to him is that he should fall so short of the gentle, loving nature of his dear Lord and Master. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1029.cfm