I always say that if you can't accept someone the way they are now, DON'T marry them. You have no guarantee that they will EVER change.
Don't even go on one date with someone who isn't a Christian. It's easier to say "NO" now than it is to break up with them after starting a relationship. Don't risk falling in love with someone you already know you won't be equally yoked with (2 Cor. 6:14). Don't be with someone who merely says they are saved-- make sure their life shows the proof of a daily walk with God.
Focus on growing closer to Christ. HE will show you the right one when it's the right time (Song of Solomon 3:5).