I respectfully don't see it quite that way.
The OP is 15. This may or may not be too young to potentially start dating. I don't know and can't remember for sure how I thought of it when I was that age.
It may possibly be good to get some experience with women in one form or another (I don't necessarily mean just in terms of romance or whatever). I personally struggled to keep myself composed with the first few women I went out with. I remember having my arm or leg shaking for the first hour or so and struggling to put words together beyond a stutter, caused by nerves. This level of nerves probably completely freaked them out big time and is probably part of the reason why I never went out with any of them more a couple of times.
For the last number of years (more or less since leaving school) I have been one seriously smooth cat

I don't believe this would be the case, had I not went out with a number of girls and made a complete mess of it when I was younger. I am glad I made a mess of things when I was 15 and was probably was better off being single then - as supposed to when I am older and meet people who are more mature. I have friends who really struggle to speak to women at all in any setting, unless they've known them for ages.
A guy at my Church was told at his previous church that he couldn't date a non-Christian. This non-Christian that he has now dated for a number of years, goes to our church and takes part in worship and other groups. They are now engaged to get married.
I do however agree that you must share a similar set of values and priorities and these will include Christ in the longer term. You can never date anyone assuming they will come to see things the way you do. To get married would be quite a different matter but at 15, that isn't really much of a consideration.
Things to remember:
Be completely open and explain that you are a Christian and what it means to you from the start.
Have realistic expectations but don't put yourself down. There is a good chance it wont go well due to your own inexperience but there is a chance it might.
If things don't go well - it doesn't reflect on you personally, although you can learn from it.
Most women you are likely to go out with are completely nuts, although not all are.
There are many good things about being single. It's only bad if you let it annoy you.
You will regret having sex if you do - so don't do it. I've only ever went out with one women who didn't respect me standing up for this. I've been offered it on a number of occasions and have always been glad I declined (as is my girlfriend when she has previously been offered/pressured by other guys)
When I first started going out with my current girlfriend, she told me she didn't wish to have sex and thought I wouldn't pressure her and that was one reason she felt comfortable with me. I know many would say I shouldn't date her because she is not a Christian but I personally don't see things that way at this current stage in my life.
I once went out with a girl who said she was a Christian and she even got baptised. That however did end really terrible. Another girl I went out with claimed to basically believe and suggested she wanted to know God but kept putting it off. That was probably my most successful relationship, apart from this one.
Sharing a similar perspective and set of values is important but I don't think it necessarily has to be as straight to the point as them having to be a Christian - when you're 15 and you're looking at getting to know the opposite sex better. If they are freaked out by you being a Christian and don't seem to understand or respect what that means to you - it's time to cut your losses.
Also remember that you never really miss out on good opportunities with these things. If you really are people who get on well, you should be able to continue to get to know each other as friends and things may take a certain course at a later date.