I'm somewhat surprised by this debate. I mean marriage isn't supposed to be like a car that you can trade out for a new one every time something goes wrong, or you find something you don't like about it. The main point yall all seem to be making is that you need to 'test out' how living together would be, because dating isn't testing that enough. Marriage is hard work, it's not like some easy thing that makes life perfect... no matter who you marry there will always be problems that you will have to overcome. Living with that person before you are married seems like just a way to have it easier to give up on the whole thing. Divorce is no big deal now, but if you are living with this guy/girl and basically functioning as if you were married, even if you aren't having sex it's super easy to just walk away from the whole thing if something goes wrong. There is no commitment. Why give everything you have, except your technical virginity, and actually there's a good chance you'll end up giving away that as well, to someone who has made no commitment before God not to leave you when you hit a bump in the road? When you are imperfect? When they get tired of the problems marriage brings? Just seems a bit lazy to me.
You get to watch and observe the person you are dating, and even before you date them. Watch how they treat little kids and older people, watch how they serve, watch how they treat their parents and family, even when things get rough. I mean it's the character that matters. If this person has a strong heart for the Lord and is really dedicated to the Lord then if you both, along with parents, or mentors feel that it is God's plan for the two of you to get married, it'll be ok. Because someone who is really committed to the Lord isn't going to give up on their marriage, even when it hurts, and it's hard, and some stupid quirk of yours is driving them crazy. You don't need to live with someone to see what type of heart they have for the Lord, and that's what really matters.
Not to mention there would be so many temptations on both sides. You'd wear way less clothing around the house usually. When you are in love with someone there's always temptations but how about when your girl friend is wearing some skimpy pajamas that barely cover her body? She's crying and wants her boy friend to sit and cuddle with her and hold her. We're supposed to run from temptations, living with someone is not going to help you resist temptations.