From the Tzemach Tzedek's answer at yechidus: It is written, "Let the wicked leave his path and the man of sin his thoughts etc."1 Aven (sin) is the same as on,2 meaning power and strength. Just as it is imperative that the "wicked leave his path," for without teshuva it is impossible to approach the Sacred,3 so must the "man of strength," one with unshakeable confidence in his reasoning, "leave his thoughts." He is not to insist, "I say so. This is what I think;" every "I", ego, is a source of evil, a cause of divisiveness.