Actually I’ve always said both. God exists ontologically and God is the only source of objective morality.
The god of Islam says it’s morally necessary to lie. The Christian God forbids lying. Therefore they cannot be the same. There are other examples of mutual exclusivity between them.
Your definition of the well being of humanity is different from anyone else’s definition. So it’s necessarily subjective. Your opinion against theirs.
Where do you access the tenets of objective morality? Where is it written down?
The God of Islam allows lying to non-muslims. This is quite different. After all, the Old Testament God forbids killing, but he bade the Jews to kill the Canaanites. He forbade adultery but taking female slaves was allowed. You have to look at who the rules apply to. In both of them.
Your definition of the well being of humanity is different from anyone else’s definition. So it’s necessarily subjective. Your opinion against theirs.
And people's definition of God, and what He wants, gives rise to just as many different opinions. That's why we have so many different religions, and within religions, so many denominations, and within denominations, disagreements. I've seen devout Freepers right here get into scalding arguments about What God Wants.
So for providing an objective and immovable line in the sand, He's no more reliable than any other human-declared absolute.