Absolute morality means if God says it then that settles it.
The problem with this is twofold.
Firstly, the Euthyphro dilemma shows that God cannot settle it no matter what He says.
Secondly, God doesn't say anything, and hasn't for hundreds, probably thousands of years, if ever. The problems of a post-industrial society cannot be found (much less solutions be given) in a pre-industrial text, even if that text were somehow divinely inspired. Where's the updates? Where's the indisputably authoritative guidance, from God Himself, on questions of interpretation?
When most of the developed world isn't interested in God's word, and the rest of them, plus the less developed world, can't agree on which text(s) came from God or on which version of any of them is the most correct, it's undeniable that an update is needed.
Is God incapable of settling the debate by issuing a new text, or at least nominating which old one is the true version, and settling once and for all what the correct interpretation is if any disputed content?
"If God says it, then that settles it" can't be true, if God refuses to say anything to settle anything.
The existence of heresy, claims of heresy, or even mere scholarly debate on the question of which scripture(s) most accurately reflect God's opinions, is clear proof that no Gods are interested in providing moral guidance of any kind to anybody.
