To try to explain my own logic here, I believe that the absolute basis of morality is not something that can be objectively proved. If you have a basic idea of what’s moral, you can think logically about how that would be applied in different situations. And if you and I share a basic idea of what’s moral, we can use that to build shared principles. But if your basic idea of what’s moral is fundamentally different from mine, all I can say is that your idea horrifies me and I wouldn’t want to live in a society based around it. I can’t “prove you wrong” in a logical sense.

This is not a belief I share with people who believe in divine command morality, nor is it an idea they typically understand when I try to explain it. As far as they’re concerned, what’s moral is what God says because God is the one who said it. When I try to get them to explain where they’re coming from, they fall back on an argument from authority: God is like a father or a king, so what God says is more important than what you say, just like what your father or your king says is more important than what you say.

Besides invoking my intense dislike of fathers and kings, this argument sidesteps the issue of why this “God” person is important in the first place. I don’t inherently or objectively place moral value on anyone, whether they’re a god or not. I subjectively value them based on my own inclinations. Saying “this necessarily must be important” is no more logical or sensical than “this necessarily must exist,” and it has no value in a serious discussion.

(I have seen another, more logical variant of this: “God is smarter than you and wants you to be happy, so if you want to be happy, you should listen to what God says.” My only response to this is that if God wants me to be happy, he’s not doing a very good job of it.)