I rather like this C.S. Lewis quote

Long since,... He had taught me how a thing can be revered not for what it can do to us but for what it is in itself. That is why, though it was a terror, it was no surprise to learn that God is to be obeyed because of what He is in Himself. If you ask why we should obey God, in the last resort the answer is, "I am." To know God is to know that our obediance is due to Him. In His nature His sovereignty de jure is revealed.