They are called the natural sciences for a reason, Dan. The observable is what the natural sciences have to work with. That is the ‘a priori’ you speak of, and that is as it should be.
How would a supernatural scientist be able to demonstrate, using the scientific method (would they even use the scientific method?), that it was the Christian God who created the universe instead of the Flying Spaghetti Monster? A defender of the FSM theology could quite simply attribute all of the actions to the FSM that you attribute to the Christian God, and the argument would be very short:
“yes it is”
“no it isn’t”
Uh, no. That is the fallacy of equivocation where the existence of natural physical laws is equated to philsophical naturalism.
"A defender of the FSM theology could quite simply attribute all of the actions to the FSM that you attribute to the Christian God, and the argument would be very short: yes it is no it isnt"
Likewise, a defender of philosophical naturalism would simply attribute all of the actions to undiscovered natural phenomena and the argument would be very short: "yes it is", "no it isn't"
Did I mention that philosophical naturalism destroys critical-thinking ability?
OK, I'll take the bait:
The first 3 are non-falsifiable, as you claim, but require faith. However, what of the last. The very crux of Christianity, and all that goes with it, lies in this simple truth. If Christ be not raised, the Christian faith is futile, foolish, and dangerous! However, if he did raise from the dead, then his claims must be true, including the first 3. Thus, the claims of John 1:1-9, Colossians 1:16, et al must be true. The New Testament is falsifiable, then, based on historical, manuscript, and internal evidences. Now, since we all spend so much time debating Evo and Creo, we must get to the root: where did life begin, and from whence did matter come? All else is moot, for they hinge on the answer to these 2 questions.
Finally, have you seriously, and investigatively, considered the claims of Jesus? Did Jesus rise from the dead???