This isn't my question, but someone I know asked this, and it is a very good question. God tells Abraham to sacrifice his son, but before he does it, an angel appears and stops him. So was that a test he failed? Did he disobey God? Who was this angel? Do we know it wasn't satan making Abraham defy Gods command? Why didn't God tell Abraham to stop Himself, if God was the one to first tell him to do it?