Chances are, if you’re asking the question, you're either feeling guilty about already engaging in premarital sex -- or you’re looking for an excuse to start.
The good news is: If you're reading this, you CARE what God thinks. Even better news is: He cares what you do.
In the Bible, premarital sex is lumped in with other “fornication” or “sexual immorality.” The short answer is: God is very much against it.
"It is God's will that you should be sanctified: that you should avoid sexual immorality." (1 Thessalonians 4:3)
The Apostle Paul reminds us in 1 Corinthians that we, as Christians, have invited Jesus Christ to live inside us. So any sexual sin we commit also stains our great Savior who, through the Holy Spirit, wants only to unite us with God.
"The body is not meant for sexual immorality, but for the Lord, and the Lord for the body." (1 Corinthians 6:13)
"Flee from sexual immorality. All other sins a man commits are outside his body, but he who sins sexually sins against his own body. Do you not know that your body is a temple of the Holy Spirit, who is in you, whom you have received from God?" (1 Corinthians 6:18-19)
In addition to breaking our fellowship with God, there are plenty of common-sense reasons to avoid premarital sex. It can result in guilt and shame, AIDS or other sexually transmitted diseases and unwanted pregnancies which may then tempt us to consider abortion.
What about those who say premarital sex is OK because God gave us our appetite for sex and therefore it must be good?
We should remember that God gave us all sorts of appetites, but our sinful nature makes it possible for us to turn even the best of appetites into gluttony.
The theologian C.S. Lewis made this point by looking at our society’s obsession with nudity as evidenced by “strip-tease” clubs.
“Suppose you came to a country where you could fill a theatre by simply bringing a covered plate onto the stage and then slowly lifting the cover so as to let everyone see, just before the lights went out, that it contained a mutton chop or a bit of bacon. Should you not think that in that country, something had gone wrong with the appetite for food?” Lewis wrote in the book Mere Christianity.
Or look at how strange it would be if we pursued food the way some of us pursue promiscuous sex. We would purchase a steak or a succulent lobster, admire it, cut off one juicy bite, chew it up, then spit it out and toss the rest in the trash. Then we would order something new and different to taste.
We would be silly to forget that food has something far more valuable to offer than the flavor. It offers nutrition – without which we would die.
The commitment of marriage is what adds the nutritional value to otherwise frivolous relationships. It offers each partner opportunities for refinement and sanctification as they work through the problems that they would simply flee in an uncommitted pairing.
We should also remember that when we resist the temptation to engage in premarital sex or other sexual immorality, we are storing up favor with God, as we see in James 1: 2-3:
"Consider it pure joy, my brothers, whenever you face trials of many kinds, because you know that the testing of your faith develops perseverance."