A Serious Question For Theists

[fr0d0]

If you're denying rational, which is what I think scientism is doing besides being self defeating (1), then I can't see how that position is tenable

Oh. That's a different definition than I was assuming. I don't think science needs to deal in that kind of absolute. But I think any discipline that purports to prove something needs to provide evidence that we can at least consider for discussion and that follows some sort of rules. And I think it's the rules part that makes the supernatural (or metaphysics, etc) impossible to verify.

What does it want to prove?

I don't think it wants to prove anything. I don't claim that God exists... I believe that God exists. I think the rule is that you can't prove it. If you could then it would be false.