A fool gives full vent to his anger, but a wise man keeps himself under control. (Proverbs 29:11)
I can certainly be a fool. My Dad always said "never fight with a fool", but I'd say, "but Dad, it's only the fools that I need to fight with"! I continue to struggle with my anger issues. Of course, I feel justified with my anger. It isn't rash, it isn't out of the blue, it isn't out of line, it isn't without cause. But what it IS, is un-Christian.