There would be less rape because no one would want to rape someone; they have a wife/husband to provide for them. Less divorces because when you would marry, you would truly understand and love one another. There would be less teen pregnancy because people would wait until they marry until they have intercourse, which is usually out of the teens. The Lord's commandments are meant to help us; the more we can follow them the better it is for all of us.
"Sex without marriage often ruins people's health and well-being. The Centers for Disease Control and Prevention report estimate that 65 million Americans have an incurable sexually transmitted disease (John R. Diggs Jr, M.D., 2001).".
Unmarried sex also can lead to a number of things, abortion, promiscuity, unstable family life, high risk of ravages to women/men and children. If two people who have intercourse, have a baby for some reason, but they don't want it, their primarily step is just to kill it. If two people that have a baby, but are not married, the child/children may have to grow up with a single parent, which is unhealthy for kids. The reason for promiscuity is that adolescents who are sexually active, and are not married, usually have sex with other people.
In unmarried couples, domestic violence and child sexual and physical abuse are highly common. Children who grow up with unmarried parents have a higher risk of being poor and uneducated when they get older. Some reasons why the kids in unmarried couples don't become as successful as kids with both parents is because each of the biological parents try to establish a home for their kids; this is something that should be done together rather than separately. "Resources such as money and knowledge are not put together toward a common goal. Skills are not passed on to progeny by absentee parents. Money is dissipated by selfish desires rather than channeled toward family.