I'm curious as to why and how you (some of you shared) have trouble being friends with those who are strong in their beliefs.

I, for one, am strong in what I believe, but I don't push it onto others. I can offer it, and it is the basis by which I offer support, even here at PC, but I don't think it clouds any issues for others.

How does another person's belief injure your own, or what about this that inflects negative feelings for yourself or the situation?

A belief system can be used to guide one in their behavior. Is it that perhaps you mean you can't be friends because you find fun in different areas? Is that what you mean, that their belief system restricts them from things you find ok to do?