I think it is worthwhile to consider one's epistemology when approaching things such as this before having a dialogue. When people come together on this subject it is important to understand how each person "knows" anything. If the only way we can truly know things comes from a naturalist perspective (those things can be tested with the 5 senses) then that will ultimately determine the value we place on the "evidence" that a non-naturalist offers.
I think that if a person can demonstrate that there are such things (not necessarily God) that exist apart from being placed under a "microscope" of sorts, then it can set the stage for a more productive discussion on the questions you have asked.
Something the naturalist should consider is the following:
What kind of physical test can they do to prove that only the things that can be observed with the 5 senses truly exist? Is that even possible? If it isn't possible to show this epistemology from a naturalist perspective wouldn't that render naturalism self-refuting?
You offered 2 types of questions. The first question was from a naturalist perspective. The others were from a cultural/Biblical validity standpoint.
Anyway, that was just a few thoughts I had.... for what it's worth. (probably not worth much :) ) Often times people don't take the time to first understand the other person's epistemology. When they don't do that they end up just spinning their wheels talking past each other on the "proof" that the other person discounts out of hand.
By the way, I am not assuming you to be a naturalist. Only your first question would I argue was from a naturalists perspective.
- RetroFit
How, I would ask, can a person "demonstrate" anything and not use what you term the "naturalist perspective"? The only alternative I can see is simply people arbitrarily agreeing to the truth of something. That, however, demonstrates nothing but the agreement, and certainly not the truth of the matter. For example, if someone says, "such-and-such is true because it says so in my holy book," that does not demonstrate the truth of the statement, even among the speaker's co-religionists.
What other possible way is there to "demonstrate" anything?