For Schopenhauer there is only one thing in itself, not many. by this he intends to belay the problems on Kant raised by Schulze, Fichte and others. That is the WILL, but this will is not automatically good. There is a non-rational aspect to God, as the verse we say in the morning states יוצר אור ובורא רע ''forms light and creates evil.'' However that blessing changed to actual words of the verse to be ''...creates darkness.'' This you can see in Job where the suffering in fact did not come from sin, but from a bet God had with the devil. The non rational aspect of God can be seen through-out the Torah. God gave Avraham a son and later told him to kill him to show how religious he is. He brings Moses to the edge of the Land of Israel but does not let him enter because Moses hit the rock similarly to what he was told 40 years prior to that right after they left Egypt. The events with David and Bat Sheva also shows this aspect where he was never supposed to be married with her and yet that is the union from which all kings of the House of David come. in the Torah there is a command to appoint a king but when Israel wanted to fulfill that command the prophet Shmuel showed to them a miracle to show that they had sinned.
This irrational aspect is because reason is a creation of God. It does not control Him.
