As a point of fact, it seems that the natural universe may not be measurable or observable at the quantum level of modern physics.
I agree that there is no reason to require that God have a physical existance in order to believe. However my original objection is to the use of observable, physical things, no matter how complex or mysterious, as evidence of a supernatural creator. That objection seems to me to be strengthened if you put God outside of physical existance.
Nobody ever mentions what seems to me to be the strongest evidence for the existance of God, that simply being the fact that there is anything at all. A void is perfect and complete, why is it cluttered up with things? Somebody must have had an idea.
I still utterly reject the idea that any physical thing offers evidence of God. Explaining complexity by postulating greater complexity as a cause just will not fit into my mind.
Very few people think things through to your conumdrum -- why does a perfect being create a universe at all?