Sex Before Marriage

My girlfriend and I are planning on getting married and I’m a new Christian. So what’s so wrong with us being involved sexually? Is there something wrong with sex? --Mike
As a pastor, I have been involved in counselling many people before I marry them. And it has happened a number of times that people would go ahead and have intercourse because they were going to get married. I understand that, and the Bible has nothing to say against that, actually. However, it is just as likely that the couple decides after a bit that they weren't right for each other and then had a messy break-up. They didn't break up because of the sex, but the break up was messy because of the sex.
In our society that promotes "safe sex no matter what the cost" the ancient wisdom about sex is neglected. Sex is there not just for pleasure, but to create commitment. It is a physical act that creates a relational and emotional bond between two people. It is intense and powerful, and if we play loosely with it, we will end up in long-term depression and an inability to connect with other people, especially the opposite sex.
Sex is really meant to be between two people. The pleasure in sex actually increases if you continue having sexual activity with only one partner, as long as they are both concerned about the other's sexual and emotional needs. This is how we are made, this is one significant way that we have happiness in our lives.
So what's wrong with sex? Nothing. Sex is great, God made it and He made us sexual beings. And He also created us to be coupled-- to be with one partner who is concerned about our needs and does all he or she can to meet them. And he made us attracted to people who have different concepts of reality and love and emotion than we do, in order to increase that love. And He made us have children to test our love and to have it grow stronger in adversity. Sex is the foundation of human life and love. It is great.
But if we go against the principle of one partner-- if we get involved with sex before we are really ready to hook up with one person-- then our search for pleasure becomes a source of tremendous turmoil and sorrow and hatred and pain. This is what the Bible says, and this makes sense with what I have seen.