As science advances, there seems to be less and less for God to do. It's a big universe, of course, so He, She, or It, could be profitably employed in many places. But what has clearly been happening is that evolving before our eyes has been a God of the Gaps; that is, whatever it is we cannot explain lately is attributed to God. And then after a while, we explain it, and so that's no longer God's realm.

The Varieties of Scientific Experience: A Personal View of the Search for God