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.
It seems that people feel that they need the Creator for pedagogical reasons, like Santa Claus or the Boogey Man. But do reasonable, rational people really need a celestial dictator to tell them right from wrong?
The god of Islam says it’s morally necessary to lie. The Christian God forbids lying. Therefore they cannot be the same.
God forbids murder, not killing.
The definition of God as accepted by Christians is not variable.
God created the universe, sustains it as we speak, and he gives us life. His authority to tell us what’s right and what’s wrong is immeasurable.
Another person telling you or me what they think is right or wrong, or a group of people telling us—this is still subjective.