It's like a system of checks and balances to me. External theology is just the "group thought" on the spiritual issue, or even just the cultural institution of some spiritual ideas; individuals need to infuse the cultural code so that it does not become irrelevant or die off as a dinosaur, while the individual can benefit from self-review in consideration of what many other people have perceived and believed over the decades or centuries.
Why is one promoted beyond the other -- and particularly a social standard that exists as its own entity rather than within a human being, for whom such standards were created in the first place?
Yes, in the end it's still the individual moral choice of the person what standards are accepted and what standards are rejected. There is no external ethos, it STILL comes to a head within each individual person.
That makes sense as well.So how can I know my moral system is superior to God's, then? Easy, just judge his system how you would judge anything else WITHOUT the presupposition he can't be wrong no matter how immorally he behaves. Then it's easy. If you think that he can only be perfect (*which means you're really just taking his word for it*), then there is no reason to have this discussion. If you're willing to take an unbiased look at both sides, it becomes clear.
(Note: You won't KNOW your moral system is better than "God's" but you can believe it to be so.)