Part of the poroblem is that even people who go to the same church ro the same mosque sometimes ahve wildly different ideas about God. And who and what God is has been interpeted on a wildly different basis over the centuries even in a singular religious tradition, such as jsut inside Islam or just inside Christianity.
Using religion as a moral guide to determine public policy is like teaching creationism in public schools. Which creation myth would you teach, and which of the 5000 recorded dieties should we follow in determining public policy?