Responses...you want responses? I can give you those...but as you seem to be ignoring me now, you will probably disregard my responses and find some way to try to insult them. But anyway,...here they go...
Sex is not what defines people. Sex is not the essence of me, and when you define your whole self as a sexual being you fragment your relationships. You define others as sexual beings and your relationships are based on sex. Unfortunately, sex is an extrinsic value and will not last forever, or even maintain the same value. This means your relationships live and die with your sex lives. This creates severe instability.
No one is "defining" their "whole self" as a sexual being. However, as I have stated before, we are mammals, mammals have sex drives, it is nature. So to deny that sex drives exist is nonsense. Every animal has criteria for mating partners. Mating calls, dances, battles...there is a reason for this. The strongest buck gets the doe, the most colorful bird with the best song gets the female, and so on and so forth. Sex IS a driving force in our lives and to put on religious blinders does not change this fact.
The other all-too-common cop-out is to say that cohabitation before-hand lets you basically test drive your partner. This also means the success of your relationship comes down to whether or not your distinct sex lives have happened to put the two of you at the same place at the same time. You do not grow together, you just hope to run into each other in the same arena of sexual compatibility. This means everything, again, hinges on sex - only this time your exclusive experiences have to match.
You do NOT want to be in the same place at the same time sexually most of the time. You talk about growth together, well, by each having different experiences or tastes in sexual behaviour and likes each gets to experience different things and learn new things they might like better that may improve their intimacy and enjoyment of each other. The thing is...by "test driving" you not only get to find out sexually what is what between two people, but the constant closeness allows you to perhaps see things about the other that you would otherwise not find out until after marriage. Things that may be too difficult to overcome. Better to find out before you lock yourself into something that may be all to difficult to reconcile.
Waiting until marriage to have sex means two things. One, each person has developed no sexual identity, and it can then be developed together. The couple discovers their sexuality together and only between the two of them. Two, their sexuality is exclusively theirs. It is not the result of others interfering or influencing. There's no risk of being incompatible, because you both start at zero. This is, absolutely bar none, the strongest sexual link that can be developed between two human beings. This kind of intimacy cannot ever be imitated or reproduced, and this kind of intimacy is the greatest indicator of a healthy marriage.
And what about those who are getting married and have sex before the ceremony? Why is the legallity of marriage so important to have between two loving partners? Why is it so hard to believe that a couple could remain together happily for many years or their whole lives and never get that peice of paper that says they are husband and wife? What about homosexuals who are currently denied the right to marry? What if they spend their entire lives together, faithful and loving? Should they never experience physically loving each other simply for the lack of a peice of paper? As for intimacy growing...refer to above response.
Someone out there will, of course, say their best friend, or brother, or somebody got married without ever having sex and they were completely incompatible. There's always at least one who uses that ridiculous excuse as evidence. All that example means is that the people either 1) were defined by sex, or 2) were selfish with sex. It simply cannot mean anything else. Two people completely devoted to the happiness of the other cannot fail, sexually, if they both wait.
Someone will of course say that they know someone who got married as a virgin and their spouse was as well and that they were completely happy. Vice versa, you can find all varieties of relationships whether they have had pre-marital sex or not that have turned out all different ways. Doesn't make any circumstance a "ridiculous excuse" and for you to classify statements you don't agree with as that just shows your naivety about life in and of itself. Sex can be pivotal to a person and that doesn't make them defined by sex or sexually selfish. If sex is painful, unenjoyable, unfullfilling, and so on then that person will be unhappy in a part of their relationship. To be unhappy in a part of a relationship provides a strain on a relationship itself. Have a serious relationship and you will undoubtedly see this for yourself. Why in the world do you think there are so many marriage counselors and sex counselors everywhere if it weren't important?