I totally agree with finally awake and sowhatnow. You aren't a believer anymore...she most likely will stay in, unless you've talked to her about this and know you are both of the same inclination. If you do stay and date her and she's a real witness, you might be hot for her, but eventually it WILL be miserable not being i agreement about the religion. You will want to live your life, she will want to not let you. You will be pressured to get married very soon, because you will want to get physical.
If you've talked about the religion and are in agreement, your chances are better. But in either case, GO TO COLLEGE. When in college write and text her and stuff. See if she is agreeing with you. Talk about meaningful things. If she's witnessy, you might meet someone else you like just as much. Your pond is currently pretty small.