The point is how DO we distinguish between someone making predictions in the name of a deity and just being delusional, from one that we can consider/believe to be a recipient of Divine revelation.
No, that's not my point or anywhere near what I said. This is another reading comprehension failure on your part.
My point is believing that the ability to prophecy with the aid of an extra dimensional deity is scientifically unexplainable in light of rejecting miracles that are not.
Believing a deity speaks (how?) to a human is no more scientifically explainable than any miracle a person wishes to reject on the basis of being unscientific.