I think non-empirical evidence is logically unjustifiable.
Some things that are non-empirical are justifiable, though very few are. For instance, gravity was a known phenomenon but was not empirically understood for thousands and thousands of years. The same could be said of electricity.
As for deities, no one can be certain of anything. It seems to me that you are arguing that a lack of evidence proves something false, but all it really proves is there is a lack of evidence and not that something cannot exist apart from certainty. But I could be mistaken, and apologize in advance if so, as I only recently stumbled on this thread and have not taken the luxury of reading every submission.
"Fix reason firmly in her seat, and call to her tribunal every fact, every opinion. Question with boldness even the existence of a God; because, if there be one, he must more approve of the homage of reason, than that of blindfolded fear." Thomas Jefferson