[Anamehuskeene]

I suppose it all depends on what you want out of this relationship and how far you see it going.
If you wish to marry her, then you have to respect her wishes and her religious beliefs and abstain from sex until either she changes her mind or you get married.

But if you do get married, how is that then going to effect your relationship.
Most Women change in one way or another when they get married.
They either change for the worst, or they change for the better.

If you get married to this girl and she has gotten so used to going without sex, then she might withhold it forever, and once your married to her, your pretty well focked! And only Divorce or the death of either of you is gonna get you out of a sexless marriage.

Even though, I'm an athiest, If I had a GF I loved enough that I would consider marrying her, even if she was deeply religious, Then I might be swayed to attend some of her meetings to see what goes on, By taking an interest in what she is doing, even if its not something you directly believe in, it might provoke a change in her, towards you.

If you think you can remain in a sexless relationship and remain faithful to her, Or you think she is your Miss.Right, then you have nothing to loose by staying with her, for the moment.
It might be that she only believes in No sexual Intercourse before marriage and a quick "hand shandy" now and again to keep you happy, is the way to go, for now.

She might even end up so sexually frustrated, that any thoughts of abstaining from sex until your married, will "go outta the window" once she gets horny enough!

Now she's had a "taste" of sex with you (pardon the pun) she might find it harder to abstain, than if you'd never done it before.
Guess that largely depends on how good you are though!