Again, I hope I can make you happy with a short answer. I have just immersed myself (no other word can be used to describe the size of that post) in another thread and I want to be careful of neglecting that one which I began in first.
Anyway, let me say that if God makes any sort of punishment for an activity, however light, it is clear that He is not happy with that activity. In that light, having a physical relationship with a woman before marrying her, is not ok as long as you marry her. It is wrong. However, to rectify the situation, God commands that marriage take place. That doesn't mean its ok for a man and woman to have a physical relationship if they are getting married anyway. I know this may seem like I am reading into the text. Please excuse that. I am just trying to answer briefly. Also, you might consider the verse at the end of Genesis 3 which talks about the man leaving father and becoming "one flesh" with his wife. While this has a deeper meaning than a physical relationship, that is certainly included.
Having covered (thought lightly I admit) the two dealing with virginity, let me say this: Concerning the other, and really all three, it stems from a biblical definition of what marriage is. Part of that is the phyical relationship and that was designed for the relationship of marriage only. Basically to partake outside of marriage is to violate God's design for life. A brief example (which I am sure might start a controversial rabbit trail): God never intended for man to be drunk but that can easily take place if grapes are allowed to ferment (sp?). Just cuz it is possible doesn't make it right. The limiting of a thing all gets back to God's original design for that situation.
Thats all I can really afford to say on the matter for right now and hope that it helps.
Russ
Ok, one last thing -
And virginity is truely a meaningless concept to begin with
I couldn't leave this one alone. Throughout all of scripture sexual purity is connected to spiritual purity. An oversimplification of the idea being you can't extremely spiritual and extremely loose with your body at the same time. Zephyr kind of hit on this with his comment about pagan religions. And, if those pagan religions were formed by people who began by rejecting God (my assertion) it would be understandable for them to rebel sexually as well as spiritually. Anyway, I am not totally devoid of attention to this thread. It is simply not my priority right now. But let me know what you think.
[edited to add postscript]
[This message has been edited by apostolos, 11-25-2003]