I asked what refutation might be available for what I called the raw divine command theory. This critique, for Lewis's A Grief Observed, is the closest I've seen to a refutation.
And so what? This, for all practical (and speculative) purposes
sponges God off the slate. The word good, as applied to him, becomes
meaningless: like abracadabra. We have no motive for obeying Him.
Not even fear. It is true that we have His threats and promises. But why
should we believe them? If cruelty is from His point of view “good,”
telling lies may be “good” too. Even if they are true, what then? If His
ideas of good are so very different from ours, what He calls “Heaven”
might well be what we should call Hell, and vice versa. Finally, if reality
at its very root is so meaningless to us—or, putting it the other way
round, if we are such total imbeciles—what is the point of trying to
think either about God or about anything else? The knot comes undone
when you try to pull it tight.