What makes you believe in one supernatural aspect of the story but not all?
Excellent question. An even better one might be,
how do Christians decide which passages to interpret literally and which ones to interpret figuratively? My religion interprets pretty much anything literally that would make sense to interpret literally, and keep the figurative interpretations to a minimum. We're probably more that way than most Christian denominations. People say that it's dangerous to take the Bible too literally. While I can understand that objection, I believe it's just as dangerous to take it too figuratively. As soon as you start saying, "Well, that's only figurative," or "That's merely symbolic," you open the flood gates. If we can't rely on the Bible literally most of the time, we can hardly expect to agree on anything, since figurative interpretations can go as many different directions as there are people doing to interpreting. If Christians would simply stick to what the Bible says,
in the language in which the Bible says it, we'd agree on a whole lot more than we do as things stand.
Probably. For example, a church in my neighborhood is considering leaving the Lutheran Church organization as a whole because of its recent increased (although still minimal) welcoming of homosexuals to the church. They think the LGBT community should still be barred from any religious center.
Nobody can agree on who to discriminate against, which is a shame really.
Well, remind them that there are a lot of Mormons out there. If anything will unite them against a common enemy, it would be that.