The writer has stated in other comments that the writer is non-binary, which is the closest I can get to an answer to the question, but the actual answer to this question doesn't matter. We can apply gender identity to humans and non-humans (e.g. animals, fictional aliens, heck even ships) but divinity is not a gender, it's a supernatural or spiritual status.

People are free to identify as whatever gender (or non-gender) they so choose but by telling me "you must accept that I am divine," we're having an entirely different discussion. By requesting capitalized pronouns, the writer is also requesting their spiritual beliefs to be affirmed, which is implicitly (and apparently intentionally) forcing the other party to change their spiritual beliefs.