I much prefer the term 'realist' and I use this if asked what my beliefs are. And of course I'll sing almost anything given the right circumstances. Churches, particularly big ones are great places to sing in, and very rarely do you get asked your beliefs which is fine by me.
I visit places of worship fairly regularly just for sheer enjoyment and often put something in the pot. I've never been asked to leave because I'm not a club member and I'm thankful for that.

Oh and old 100 is one of my faves!