If you were gay would you be friends with people who thought being gay was wrong for others?
It depends on the person. I've had friendships with people that differ wildly from me on subjects that often cause division among people. Sometimes I did it by keeping off the subject in our conversations and concentrating on things where we did agree. Other times we would enjoy long and sometimes loud discussions on the subject, but always coming back to the position that our friendship was more important than being right about something. It's not as if either one of us could actually do anything about it.
At other times, there have been people that were so obsessed with something, and talked about little else, that our interaction became too uncomfortable to continue.
I will say though that a really deep friendship (rare!) is difficult to attain when you are editing your remarks all the time.
What's more likely to break up a friendship for me is what a person does, not what s/he says.