Is there a word for the process of applying heavenly-derived arguments to terrestrial issues? For example,
“John Doe argues against abortion because his Catholic faith says it’s wrong. John’s argument is X-ical.”
Where X is something like tautology. I feel the word “religious” doesn’t sufficiently convey the incongruity of using out-of-this-world logic to this world.
If you are looking for something akin to tautology, then perhaps “begging the question“, which means “begs that the conclusion be admitted as an axiom,” rather than the modern (typical) usage “forces me to ask” that one sees everywhere anymore.
If you feel frisky, you might call it an “appeal to (false) authority.” which means that the authority is being given a pass on veracity without actually meeting a standard of proof.
It is not necessary for you to wrap your critique in the idea of religion, the fallacy you are attempting to point out is agnostic.