The title pretty much asks the question, but let's set the stage like this:
Two people meet in High School, have sex, then eventually get married.
What does the bible say about sex prior to marriage in general?
What does the bible say about sex prior to marriage, but leads to marriage?
Premarital (aka extramarital) sex is fornication, which is sometimes differentiated from adultery. While adultery is specifically forbidden in the 10 Commandments, it would appear the Bible has the same opinion of fornication. There are times when the two terms are used interchangeably as well.
All from the KJV:
Acts 15:20 But that we write unto them, that they abstain from pollutions of idols, and from fornication, and from things strangled, and from blood.
1st Corinthians 6:18 Flee fornication. Every sin that a man doeth is without the body; but he that committeth fornication sinneth against his own body.
1st Corinthians 7:2 Nevertheless, to avoid fornication, let every man have his own wife, and let every woman have her own husband.
1st Thessalonians 4:3 For this is the will of God, even your sanctification, that ye should abstain from fornication:
So it looks safe to say that "Thou shall not commit adultery" also applies to fornication. The colloquialism "living in sin" is accurate.
It doesn't specifically say "Even if you plan to get married, fornication is still a sin." But the 1st Corinthians 7:2 reference is pretty close. To avoid fornication, get married.
“Fornication” (porneuo) is often used as a noun in the New Testament, but in 1 Cor. 10:8 is a present tense verb. Although it is a verb, it still describes all types of sexual sin. For other places where fornication occurs as a noun see 6:18, and these references in the book of Revelation: 2:14, 20; 17:2; 18:3, 9.
Whether used as a noun or a verb, fornication describes departures from God’s “religious norms (e.g. homosexuality, promiscuity, pedophilia, and especially prostitution” (Colin Brown, 1:497).
Brad Price www.abiblecommentary.com
Zombie post, ooooo! Anyway, you're all assuming that the traditional modern marriage is the way it's always been done. It isn't. Would it surprise you that there are no less than three solid models of marriages taking place in the book of Genesis. A good prerequisite for answering this question is a knowledge of how the Bible says to get married in the first place. It's not in a civil ceremony. It's not a magical marriage license. The only thing the patriarchs did was gain permission to marry the woman in question and take her home. All the feasting and such and so forth were put forward by a pagan, unbelieving Laban.
Permission plus sex equals marriage. Period. The ceremonies are traditions of men. Period. To demand a civil ceremony is to effectively render unto God that which is Caesar's. And make no mistake, with all the gay marriages and no fault divorces, civil marriage is absolutely and unequivocally Caesar's marriage.
Now, marriage is a covenant. It's not something to be taken lightly at all. You are forbidden to divorce under the new covenant except for fornication. Because sex equals marriage.
