Why did God do Satan’s bidding?

[Angrboda]

One of the rather simplistic lessons drawn from Job, often, is that we don't have the moral authority to condemn God or his actions. If this is the case, does it not also follow that we lack the moral authority to justify him? If his morals are indeed beyond the pale of our meager sensibilities, the appropriate conclusion would seem to be that we can't know, that we must remain agnostic on the question of whether the God we follow is moral or immoral. That leaves me with some profound difficulties in concluding that God's commandments are in and of themselves moral, if we are indeed ultimately unable to assess his morals. If all of the above follows, why follow God's mandates at all? Might as well get out the I Ching and decide the fate of prisoners with the random alignment of a throw of bones; unknowable is unknowable, for both good or ill.