Cohabitation, Commitment, and Intimacy
There are many people today living together without being married. A good question might be: "What's wrong with that?" Without addressing the moral and biblical angle of the issue, let me talk about intimacy and why married (committed) couples can enjoy much greater intimacy than those unwilling to commit.

Cohabitation Increases Chance For Divorce
If you live together with someone before getting married, your chances of divorce increase significantly. Also, almost every problem people think they are avoiding by living together actually increases -- abuse, infidelity, breakup, etc.