How different is too different to be friends?

I need other people's opinions. Lately, I have been internally tormented. I've made new friends, whom I like very much, but we have some pretty big differences. I also have old friends and acquaintances whose status messages I can't help but notice. So, here is my question: how different is too different to be friends?
There are some people who the minute you meet them you learn things about them. Like when they say "let's get together Thursday because Wednesday I have Bible study." Others you notice on Facebook that they have written "What were they thinking passing that law in Maine?!" or it pops up in your feed that so-and-so "joined the group 'Pro-Life'." None of these things are bad, but let's take me for example (since I'm writing this and basing this on my own feelings).
Now that I have learned information that I didn't previously know about the other person, do I need to disclose information about myself? Is not doing so a lie of omission? I don't think that I should go writing on people's walls that it's completely ridiculous to take away a woman's right to choose what she can and can not do with her own body based on when you personally feel a mass of cells is given consciousness. I think I would feel awkward (not to mention rude) walking up to a person and saying "I happen to think that the Bible is a bunch of gibberish put together by Kings to conform the masses and impose their beliefs." Most people really don't want to hear that I am Pagan, but I also don't particularly need to know that you are Christian either. I've never had any problems with any religions as long as there is the fundamental belief to live and let live. That kindness and charity matter much more than which God you attribute your existence to. We are all here. The good, the bad and the ugly. Shouldn't it be more important to use the time we have on this earth to spread love, understanding and equality? Not segregate and scorn those who don't agree with us?
I realize that this is my personal space. I can write my own feelings and beliefs here and hope for support. That is one amazing thing about the internet. You have your own personal space too, and I would never encroach upon your right to say what you feel. But my original question stands, can we be friends? Can I accept that you will always think same sex couples are wrong? Can we coexist when you think that I am a heretic and destined to burn for all eternity? What are the deal-breakers of friendship?