It is also interesting to see how the idea of being kidnapped, visited or sexually molested by supernatural entities has changed with culture. In the witch crazy of the middle ages it was witches and demons, in the spiritual crazy of the end of the 18th century and early 19th century, the alien crazy in the 60s and 70s.
It isn't an assumption. It is a tautological truth (and therefore uninteresting) within your own position. If valid supernatural beliefs are beyond science, they cannot by definition be empirical. They would have to
"If you want to reason about faith, and offer a reasoned (and reason-responsive) defense of faith as an extra category of belief worthy of special consideration, I'm eager to [participate]. I certainly grant the existence of the phenomenon of faith; what I want to see is a reasoned ground for taking faith as a way of getting to the truth, and not, say, just as a way people comfort themselves and each other (a worthy function that I do take seriously). But you must not expect me to go along with your defense of faith as a path to truth if at any point you appeal to the very dispensation you are supposedly trying to justify. Before you appeal to faith when reason has you backed into a corner, think about whether you really want to abandon reason when reason is on your side. You are sightseeing with a loved one in a foreign land, and your loved one is brutally murdered in front of your eyes. At the trial it turns out that in this land friends of the accused may be called as witnesses for the defense, testifying about their faith in his innocence. You watch the parade of his moist-eyed friends, obviously sincere, proudly proclaiming their undying faith in the innocence of the man you saw commit the terrible deed. The judge listens intently and respectfully, obviously more moved by this outpouring than by all the evidence presented by the prosecution. Is this not a nightmare? Would you be willing to live in such a land? Or would you be willing to be operated on by a surgeon you tells you that whenever a little voice in him tells him to disregard his medical training, he listens to the little voice? I know it passes in polite company to let people have it both ways, and under most circumstances I wholeheartedly cooperate with this benign agreement. But we're seriously trying to get at the truth here, and if you think that this common but unspoken understanding about faith is anything better than socially useful obfuscation to avoid mutual embarrassment and loss of face, you have either seen much more deeply into the issue that any philosopher ever has (for none has ever come up with a good defense of this) or you are kidding yourself." (Dennett, Darwin's Dangerous Idea, 1995)
Stenger, Victor, "God: The Failed Hypothesis -- How Science Shows that God Does Not Exist", 2007 is good book for an antidote to the "religious beliefs are beyond science / science or philosophy has not refuted religious beliefs" position.