Theology

Lunarians need a source of energy - antimatter - whereas elves just need to know the right spells. Poul Anderson's creative versatility and literary skills enabled him to construct, with apparent ease, fictional narratives based on either of these two very different sets of premises. Fantasies can assume either polytheism or medieval monotheism. Sf features characters who at least believe either in diverse monotheisms or in alternative religious metaphysics. Norse and other deities can appear as fictional characters in novels or short stories. The One God of several well known scriptural traditions intervenes less frequently but can be there when needed. 

Thus, the content of religious beliefs is at least a major background issue in Poul Anderson's works. For what it is worth, my most recent foray into theology, an attempt to improve on an earlier version, and now entitled "Prophecy And Contemplation," is here.