As it happens, aside from a church, I also attend a place of worship for another religion which I do not belong to, nor have/will I ever. But I attend as often

As it happens, aside from a church, I also attend a place of worship for another religion which I do not belong to, nor have/will I ever. But I attend as often as I can for cultural and social reasons, including participating in religious festivals. Never had a problem. I have never pretended to be something I am not. It is not immoral at all. If someone asks, just say you are not a Christian and you are just checking the place out. Don't lie or pretend to be otherwise. None of the Churches I have been to would care if you are not a Christian, but if they do care, go to another church. Churches vary a lot in beliefs and culture. I would not try engage in religious debate to prove their God does not exist ... no religious folks like to hear that (and some may be very offended if done inside a church). If you are young and near a college, go to a college-orientated church (just about any church close to a large campus).