Nope, unless you're going to be a total dick to them about their views.

That would depend on who you ask and the context to which it's asked in.

It shouldn't be, but it starts arguments :[

If it's out of the blue, yeah. Just a little uncalled for. But if you're close with them it wouldn't be a problem.

I don't mind being asked what my religious views is but from past experiences, the outcome was irritating.

It's not rude to ask what a person's religious views are. But you shouldn't press on it too much, I suppose until you got to know them. And you have to remember to be respectful, and not talk down on them.

I don't think it's rude, but ONLY if the person you're asking is someone you know well. Otherwise, I really don't see any reason to ask about stuff like that, unless the other person volunteers the information first.

I don't think it's rude, but dangerous. People get really defensive about religion, I they are not strong enough in their believe the could get mad and leave. That's only if there's a debate of course.

"Questions are never indiscreet. Answers sometimes are."
--Oscar Wilde

I agree with good old Oscar

Why would it be? Unless your condemning them or something.