I don't understand how God is even meant to secure the objectivity of ethics
A lot of the general public (whether religious or atheist) seems convinced that morality can only be objective if there is a God. They are incorrect. Moral realism is most often defended on secular grounds. However, my question is not about that, but this:
Assume that a fact is objective if and only if it is that fact is mind-independent. That is to say, an objective fact is such that it obtains independently of anyone's mental states or mental dispositions (e.g., regardless of what anyone believes, assumes, thinks, feels, or desires).
That "anyone" includes God, so if moral facts depend on his judgments (his condemnation, approbation), or even his mental dispositions qua perfect being (i.e., his disposition to love), then it is not objective in the sense just specified. From my perspective and understanding, it seems that the objectivity of ethics requires that it be relatively independent of God. Can you explain why I am confused?