I appreciate the tone of respect that I read into your question.
Just the fact that you would ask a person how they prefer to be approached is a great start.
I am generally up for dialog with people of faith, when the tone remains even and respectful and each party to the discussion is open to hear another viewpoint.
I was a "person of faith" for many years and then came to other conclusions. It doesn't mean I don't believe in God, I have just another way of knowing God.
Having been a "person of faith", I feel deep understanding for those who are on that path and would not try to convince them otherwise.
Similarly, I do not choose to be approached by a person who is where I was, telling me that their version is the only or best way.
I do not choose to go backwards (for me, it would be backwards, but that is not any reflection on another's path.)
A good beginning question is simply, "Are you open to discussing the matter of faith?"