Tolkien's fictional spiritual world is a complicated mélange of Christian and Germanic-pagan.
With a dash of Kalevela, according to something I stumbled across in a Wikipedia wander he other day.
You could throw that in under “Germanic paganism,” or you could dump it in with “All that Greek stuff and whatall.” For my Pat, the Greek Geek, it’s interesting to look at the ways Tolkien’s Ainu and Valar and Maiar are similar to Greek gods/spirits, but different, and similar to Norse deities, but yet, and have connection with archangels, angels, and demons, but not exactly like ...
As a writer, though, Tolkien really throws himself into the Nordic milieu, and then he draws himself back ... Oh, wait a minute, I don’t really worship Odin, do I? What was I thinking?
I think it comes back to the existential doubt, Is God really on my side? What is He like? Can I get on His team? And then you throw in your poetry, and it gets complicated.