Great question. You asked for advice on how to talk to him, but I'm not convinced that's the advice you need. If he's hesitant to talk about God and faith, and you're not seeing the fruit of salvation in his life (Philippians 1:11), it may be that he's lacking what should be the #1 quality on your list: that he be a godly guy and spiritual leader! Even if he has all the other qualities that you know you're looking for in a guy, if he's lacking the most important one, I'd keep looking.
As far as the "something missing" between you, I have to say that it is definitely possible to meet and really care about a guy who seems to be perfect for you "on paper," and still have the nagging feeling that something just isn't right—that something is missing. It happens all the time, actually. A lot of girls try to ignore that feeling; they try to convince themselves that they'll grow to care about him more as time goes by. But that sort of thinking never works, and then months (or even years) down the road they have a messy breakup because they hung on too long.
Personally, I think that "something missing" feeling is usually God's quiet whisper to our hearts, telling us that we aren't where He wants us to be. We'd be really stupid to ignore it. God always knows what's best for us. He knows us (and the guy) much better than we do. So if you feel that maybe your boyfriend is a really great guy but not God's best for you, break things off now. It's not fair to either of you to ignore those feelings.
I know some of this may be hard to hear, sis, but please know that I write it out of sincere love for you and a desire to see you experience God's absolute best in your life, not just good enough.
Love,
