@Coti,
Two things. First, I applaud your expressed desire to be married rather than just live together. As a Christian, my views on the sanctity of marriage and the belief that sex should be only between married couples is a core belief.
That said, I am confused by how and where you seem to draw a line between your desire to do what you believe is right and your relationship. While you did not indicate this in your post, I get the idea that before you moved in with him you were sleeping with him. If that were the case, then I don't understand why the simple act of moving in with him is now causing you any problem. After all, nothing has really changed between the two of you except your address. As a Christian, it is not the living together that is sinful, but the intimate relationship you have with him outside of marriage. In other words, you are giving him mixed signals. You tell him you want to honor God by getting married, yet all the while you are dishonoring God by sleeping with him. From his point of view, why should he get married when he has all the benefits of marriage right now?
I do not not mean to judge you, so please do not misunderstand what I am saying. What you do with your life is between you and God. I am just pointing out that what you are saying and what you are doing can be confusing to him.
Anyway, as far as advice, I can give very little. You want to get married (doesn't really matter why) and he does not. You must either accept things as they are until he decides he wants to marry, or you can move out if not getting married is a deal breaker.
Either way, good luck to you. (Hope I did not sound to preachy those first two paragraphs.)