The most interesting questions are the ones that you can't ask. But, if you're adventurous:
Does religious wisdom come more easily to people of certain intelligence, race, religion, and/or political persuasion? (Related: are the wisdoms of different religions culturally-dependent, or universal?)
For those who are able, how best is it to develop religious wisdom? Is this entirely divorced from training in epistemic and instrumental rationality?
What is your favorite argument(s) against the existence of God?
Is widespread public atheism, homosexuality, abortion, etc. necessarily a sign of civilizational decline?
Is superintelligence possible? If/when it happens, would it be proper to refer to such a being as a God?
Briefly explain the b******k and ask if their God is as vengeful.
Can your particular creed survive another thousand years, provided that humanity can?
Given you, your philosophy friends, and a bunch of math experts, how long would it take to transform your theses into something that atheist scientists would care about?
If your God were made flesh, would he best resemble Jesus, Zeus, or Cthulhu?
I am about to graduate from one of the only universities in the world that has a high concentration of high-caliber analytic philosophers who are theists. (Specifically, the University of Notre Dame, IN) So as not to miss this once-in-a-lifetime opportunity, I have sent out emails asking many of them if they would like to meet and discuss their theism with me. Several of them have responded already in the affirmative; fingers crossed for the rest. I'm really looking forward to this because these people are really smart, and have spent a lot of time thinking about this, so I expect them to have interesting and insightful things to say.
Do you have suggestions for questions I could ask them? My main question will of course be "Why do you believe in God?" and variants thereof, but it would be nice if I could say e.g. "How do you avoid the problem of X which is a major argument against theism?"
Questions I've already thought of:
1-Why do you believe in God?
2-What are the main arguments in favor of theism, in your opinion?
3-What about the problem of evil? What about objective morality: how do you make sense of it, and if you don't, then how do you justify God?
4-What about divine hiddenness? Why doesn't God make himself more easily known to us? For example, he could regularly send angels to deliver philosophical proofs on stone tablets to doubters.
5-How do you explain God's necessary existence? What about the "problem of many Gods," i.e. why can't people say the same thing about a slightly different version of God?
6-In what sense is God the fundamental entity, the uncaused cause, etc.? How do you square this with God's seeming complexity? (he is intelligent, after all) If minds are in fact simple, then how is that supposed to work?
I welcome more articulate reformulations of the above, as well as completely new ideas.