Didn't God create "the materialistic God"?
We need no "objective basis for morality." We protect as many people as we can through laws we create for ourselves, by ourselves. This has nothing to do with "each man does what is right in his own eyes." We live in a society; we attempt to protect people from harming themselves and others. God remains absent.
In your view god of materialism only, created God. God created the material world but not the god of the material world which obviously is not a necessary being having come into existence from something else.
If man creates his own laws then each man does what is right in his own eyes. Take Nazi Germany for example but there are many more.