Hashem will fight for you, and you shall remain silent. (Shemos 14:14)
With our ego standing in the way, we are incapable of waging a machlokes l'shem Shamayim. What we perceive to be G-d's fight is often really our own fight disquised in religious trappings. With the knowledge that a human being is unable to remove his ego from his actions, Hashem is telling us in this pasuk to remain silent and let Him take care of His own battles.