Heck, if I unfriended everyone on my list who thinks I am going to hell because of my religious beliefs, I would have very few friends. It doesn't exactly feel great to know that friends and family think of me that way but there isn't anything I can do about it. I have blocked a couple people from appearing on my newsfeed because I got tired of seeing their religious and political rhetoric every time I signed on, but they have no idea I blocked them. For the most part though, I just ignore things like that. I have only ever unfriended on person and that was because she posted something controversial and when I had a dissenting opinion, told me she didn't want to hear my opinion. Fine, you don't want me to post simply because I disagree with you, then you don't need to be on my list. She wasn't a good friend anyway.
As far as friends messaging you over your decision, that is too bad. I would hope that most people can be adult enough to let the people directly involved figure out their own business.