Isn't that what scientists do? They set their own standards on what is allowed in science by a priori demanding that all existence only be explained via natural means? Therefore they can only reach natural conclusions?
In what way do non-natural conclusions explain things? Give me an example of one. And I mean actually explain, with math. If you can do that, then what you actually have is a natural explanation. Sure, you might say the sun is pulled across the sky by a charriot-riding god. But when that god does it on a path that is 100% predictable mathematically, and never, ever deviates, well, you kind of don't have a god so much as you have a natural phenomenon that follows a natural law.
That's the thing about supernatural explanations. They don't actually explain anything. Example: What makes life? A soul. Does that actually explain it? Heck no.
[edit - hit the post button too soon, accidentally]
Not only is a soul not observable, it ignores chemistry and everything else. And if you simply stick to that answer, you never get to the bottom of it. So, "supernatural explanation" is really a contradiction in terms. It is a cessation
of inquiry, and it explains nothing.
In every case where natural explanations have gone up against supernatural explanations, natural has won every single time. That is neither coincidence nor an accident.