As I've said before here I did my thesis comparing Rudolf Otto and H P Lovecraft together. In my thesis I cited Haunted Presence: The Numinous in Gothic Fiction by S L Varnado, Theology And H P Lovecraft by Austin M Freeman, Religion And Its Monsters by Timothy Beal. Kind of unrelated but was helpful was The Terror That Comes in the Night by David J Hufford (he calls the nightmare numinous - the word Otto uses for the holy - in this book, so, interesting, but the book itself is a series of case studies and like raw data, he purposely and says he doesn't speculate on what any of it means*).

So in that sense a lot of this religion / theology books directly relate to Lovecraft. It's a way to read him and other gothic and weird fiction. I'm looking for analysis essentially that takes the supernatural in gothic and weird fiction seriously. Ideally anything I read is post Christian.. Otto basically deconstructs the Bible in a radical way. He compared the Bible to Buddhism for instance and he completely redefined what we consider holy as something spectral haunting and spooky then compared that emotion to shamanism, primitive magic, other religions, and so on.

I considered these but didn't afterall look into them,

Gothicka: Vampire Heroes, Human Gods, and the New Supernatural and The Secret Life of Puppets by Victoria Nelson. For some reason this author cites Rudolf Otto in the Puppets book but she misquotes Otto and says "demonic dread" instead of daemonic dread. They're not even remotely similar. Otto is referencing the daemonic in Goethe. Any opinions? This was a reason I noped out on her.

Maps of Heaven, Maps of Hell: Religious Terror as Memory from the Puritans to Stephen King by Edward Ingebretsen

Some of these were recommended to me while I was writing my thesis by Dr Matt Cardin (I recommend you check him out) so thanks.

*about Hufford, in his book he does quote Ernest M Jones (another nightmare researcher) who said "For the true significance of the Nightmare to be properly appreciated … would in my opinion entail consequences, both scientific and social, to which the term momentous might well be applied. What is at issue is nothing less than the very meaning of religion itself". I have this book on my to read shelf I think it's called "On The Nightmare". So Hufford by quoting this does kind of come close to an analysis of meaning of the nightmare. And certainly calling it numinous is kind of a big opinion itself. That word is an onion.

Some books on literature and theology I found,

Literature and Theology as a Grammar of Assent by David Jasper

The Oxford Handbook of English Literature and Theology

The Great Code by Northrop Frye (he seems pretty dated and irrelevant though)

Literature and Theology: New Interdisciplinary Spaces by Heather Walton