<<And, I might add, the burden of proof rests on those who are trying to
prove that such a standard exists.>>
Why? Because you obviously can't meet your own burden, viz., to prove that God
and objective morality do not exist?
Where does it say Russell Stewart gets to decide who has what burden of proof?
You can try (so far without success) to attack one side; but sooner or later
you're going to have to mount your own case.
We're waiting.