Proverbs 26:4, "Answer not a fool according to his folly, lest thou also be like unto him"
Paraphrased by anonymous:
"Do not argue with an idiot. He will drag you down to his level and beat you with experience."
Many times an argument becomes a foolish bash session. You don't have to answer people according to their folly. If we enter into a bashing session, we end up just bashing each other down to the ground, making all of us look more foolish. Then we'll all show our experience in being foolish. ;O) If we are all honest with ourselves and with each other, we could all admit how foolish we tend to be at times.