I am convinced that God is not just trying to make life hard when he gives us limits. He knows what is best for us. I believe that sexual intimacy is, created by God, to serve as a truly bonding experience. It can create such a strong connection, that, it should not be entered into lightly. I sincerely believe that people stay in unhealthy relationships, because they have been sexually intimate and the resulting bond is hard for them to overcome. On the other side, individuals who have been quite promiscuous, may have calloused this bonding process. Making it difficult for them to fully experience the joy and intimacy this bond could create, once they are married. It’s not that God is trying to control or limit us. God wants us to have what is best. Waiting helps us to experience the best, most complete bond. A bond/intimacy/connection reserved for marriage.
The research in this article seems to concur.