If someone has turned their life around and decided to live a pure life from here on out and have been forgiven by God...then who are we as Christians, the body of Christ, to judge and not do the same?. I think saving sex for marriage is a wonderful thing, I'm not saying it isn't in any way shape or form. But, so many times I think too much emphasis is placed on virginity. I mean isn't there so much more to a marriage partner than the status of their sexuality? I, personally, rate character, personality, interests and goals so much higher than whether or not they're a virgin. And if you met that perfect soulmate for you, would you really suddenly not be interested if you found out that they had been sexually active in the past?? I certainly hope not, but then again, who am I to judge?
I think Princesakristina makes some excellent points... but I do think we are allowed to tell God what we may or may not be comfortable with and that's all right--after all, virgins, I would guess, are fairly rare these days (from what I know in talking honestly with people) and if everyone wanted only a virgin, there are probably a good majority of us who would die off without every marrying.
I'm not asking for a virgin in particular (but I certainly wouldn't look down on one if that's what God had for me) but for myself, I would not be comfortable with someone who has a vast history of partners, depending on their situation. I guess it may also stem from the fact that I'm a little older, so the guys I've met tend to have histories with bigger numbers than say, someone who is 24.
It really would depend on the situation though. For example, I was once dating a guy who had notes and study comments written all over his Bible (it was obvious he studied it very well, and often), as well as being able to quote Bible passages right and left in addition. He was raised in church and could really "talk the game."
However, he didn't go to church, wasn't plugged into any outside Christian support network... and told me that sex was the biggest weakness in his own personal life. He'd lived in many places... and had always sought out the underground world in each place out of "curiosity"--sex clubs, sadomasochism, prostitution, etc. (And I'm not meaning to shock anyone here, this is the truth--I'm hoping others will learn from my naivete and stupidity.)
He claimed he had changed his life around (but yet, as I said, he wasn't interested in being part of a Christian network--that should have been a huge red flag right there for me, because addictions are not conquered alone, but I was younger and more willing to believe back then.) So... I decided, who am I to judge? We dated for a few months... he would say things like, "C'mon, you know you want to marry me," and would talk about it frequently.
Then I found a letter he had written (long story, but I do think it was God showing me his heart) to a girl he worked with... let's just say... he was meeting me for dinner that night, and then in two days... was meeting with this girl so that he could carry out the other areas of his life he claimed to be reformed in.
I have just learned to be careful, pray, pray, pray, and seek Christian guidance in any major decision regarding relationships.