Tolkien was a devoted Christian, a Roman Catholic. Where was God in his mythology some people wondered?
I know people who see Middle Earth full of pagan witchcraft. I think if you have even a cursory knowledge of paganism looks like see that it didn’t get the memo about when to show up. And black magic? Well yes, but it’s also quite different and intentionally vague. (Entire books have been written about this by the way.)
Carpenter had this to say about God in Middle Earth:
Tolkien’s universe is ruled over by God, ‘The One’. Beneath Him in the hierarchy are ‘The Valar’, the guardians of the world, who are not gods by angelic powers, themselves holy and subject to God; and at one terrible moment in the story they surrender their power into His hands.
Tolkien cast his mythology in this form because he wanted it to be remote and strange, and yet at the same time not to be a lie. He wanted the mythological and legendary stories to express his own moral view of the universe; and as Christan he could not place this view in a cosmos without the God that he worshipped. At the same time, to set is stories ‘realistically’ in the known world, where religious beliefs were explicitly Christian, would deprive them of imaginative colour. So while God is present in Tolkien’s universe, He remains unseen.
When he wrote the Silmarillion Tolkien believed that in once sense he was writing the truth.
-Humphrey Carpenter, J.R.R. Tolkien: A Biography, p.99