Here in the southern Bible Belt, it is common for people to ask you "What church do you belong to?"
They don't ask you IF you belong to a church.
They ask you WHAT CHURCH you belong to.
They are quite shocked if you answer "Mormon." Some don't know what a Mormon is. Others know the Mormons as a non-Christian cult. Alot of times, they are rabidly anti-Mormon. A few (but not many) know other Mormons -- usually decent sorts of poeple -- and as a result, have no problem when you say you are Mormon.
Moved to Dallas recently and was shocked at how often I am asked what church I go to. It's normal,casual conversation here. I think it's rather intrusive. My new OBGYN asked me what church I attend- while doing the exam, as if something in my vagina depended on that little detail. The first couple of times I answered with, "we're atheists.". I got shock and awe faces. One lady dropped her fork as her eyes bulged out and she exclaimed, "you're a what?!?". I now say, "we aren't religious," just to save myself the time. Guess it depends on where you live.
I have a lot of people from different religions ask me this question. Sort of. Whenever new people ask me where I moved here from and I say Utah, the next thing they ask is, "Utah, really? Are you a mormon?"
I love saying no. Sometimes I have to remind myself to say it politely and avoid the eye-roll.
I know many people ask a person what their religion is (especially in the south). But only mormons assume you might be part of their religion while other people know you might not be a part of their religion.
What I do not like is the reference to "the church" meaning mormon church. This is mostly Utah and around mormons. Outside of Utah, it is totally different. Mormon is not even in the discussion. But, if you are in the south-bible belt-I would imagine that it is just Christian--being saved. If you are in an area with a predominant religion, then you will get questions from that religion. So, it has to be different in every region of the country. Within the cult, it is church this and church that, he or she would make a good cult member, the cult is this and the cult is that and we are going to Celestial Kingdom--too bad for all those sorry people that will not, etc.