As iron sharpens iron, so a person sharpens the countenance of his friend. (Proverbs 27:17). Metal workers will tell you that when iron sharpens iron, sparks fly. There is a context behind that, that of friendship, and probably also some Hebrew culture with a history of pretty, ah, lively discussions, so it might not apply as much to this situation as I would like. But it's a favorite verse of mine.

Peace and civility cannot exist unilaterally; it only takes one to start a war. Rather than suggest that others behave themselves, perhaps we should encourage the developing of a thicker skin, or a more discriminating filter in whose communications we let affect us. One of our wisest here has "examine what is said, not who speaks" in his signature, but I've always found that to be poor advice, at least when I know the speaker. I need to guard against prejudice, but there are people here whose history very sharply informs how seriously I take what they say, mostly to the positive.