Since her parents are very religious, I'm willing to be the "equally yoked" conversation has been talked about in that family more then once. Meaning that it's been ground into her more that if both people do not have a strong faith in the same religion, the pair are bound to fail as "god isn't the foundation" so to speak.

My wife was very strong in her beliefs when we were dating, I'm more open to that sort of thing, but I believe there is a god. I'm not into religion at all, but she was. Hell I've even had her mom tell me we need to be equally yoked, I was like "oh ok, sure". But during the dating process, I made it clear in no uncertain terms, that I would NOT be railroaded in becoming religious, even though her family believed it was best. Trust me when I say that caused many a fights, but I did not back down. Now however, we have a very open relationship regarding religion. Before she couldn't even talk about evolution, she would get too upset, now however we have many very good discussions about that and other things. I think what it boils down to is that both people need to be willing to be open minded about the other's views on the subject, even if they dont 100% agree. If she can't at least acknowledge that your views may be different and accept that then you don't need to waste your time. Saying she needs you to be in some religious group to make her feel ok is in a way already an ultimatum and thats not good. I think however your getting way ahead of yourself with the talk of being the one. Knowing someone as a friend for 3 years isn't the same as dating someone for 3 years. I dated my wife for 6 years before we married, I only plan on getting married once, so I had to make damn sure it was gonna be right for us both. Take your time, don't bend yourself to her expectation of what you should believe in or participate in. If your a member of some type of religious group simply for approval and acceptance from a significant other, then my friend your in the wrong relationship, and it WILL fail.