Without wood a fire goes out; without gossip quarrels cease. As coals are to embers and wood to fire, so is a contentious person to kindling strife.
Proverbs 26:20-21 TLV
It is frequently better to let a disagreement go than to keep trying to prove your point. People who are often involved in controversy are usually the cause of the controversy. Unless controversy is what you want, you might need to cut them out of your life.