Francois Fenelon (He was a Christian who was insulted and exiled for his beliefs)
“Do not get angry about what people say. Let them talk while you try to do God’s will. As to the will of other people, you could never come to the end of satisfying it, not is it worth the trouble. Silence, peace and union with God ought to comfort you whatever people may falsely say. You must be friendly to them without counting on their friendship. They come and go. Let them, go...they are like chaff scattered by the wind.”
“Bearing Insults” from “The Royal way of the Cross.”
I have definitely learned to leave a debate with dignity when someone else is embarrassing themselves. Not always.... but mostly.