Interesting topic, and one that most Christians would respond to with a "Yea, duh, of course." But there are some people (perhaps well-meaing, perhaps not) who contest this belief. But is it just a belief or is it spelled out in Scripture? This was a question a young man asked his pastor recently. Not anyone I know, but I relay the story from someone else.
The young man was living with his girlfriend/fiance at the time with full intent to marry her and his arguments on the matter made sense. I mean, what does it matter, if we are going to be married anyway? Does the marriage certificate add any validity and meaning to a commitment we've already made to each other before God?
The pastor was baffled and spent days searching Scripture but returned to the man saying that he could find no specific command against per-marital sex. Really? This equally baffled me because even as a numbskull lay person I could think of numerous passages in both the old and the new Testaments that spoke against sex outside of marriage
Does the Bible specifically say "Thou Shalt Not Have Sex Before Marriage" ? NO
But here are a few things it does say:
But fornication and all uncleanness or covetousness, let it not even be named among you, as is fitting for saints Ephesians 5:3
Therefore put to death your members which are on the earth: fornication, uncleanness, passion, evil desire, and covetousness, which is idolatry Colossians 3:5
Do not be deceived. Neither fornicators, nor idolaters, nor adulterers, nor homosexuals, nor sodomites, nor thieves, nor covetous, nor drunkards, nor revilers, nor extortioners will inherit the kingdom of God.1 Corinthians 6:9-10
Marriage is honorable among all, and the bed undefiled; but fornicators and adulterers God will judge Hebrews 13:3
But that we write to them to abstain from things polluted by idols, from sexual immorality, from things strangled, and from blood. Acts 15:20
What is the definition of fornication?voluntary sexual intercourse between two unmarried persons or two persons not married to each other.
In his instruction to the Corinthians, the Apostle Paul says the following
But I say to the unmarried and to the widows: It is good for them if they remain even as I am; but if they cannot exercise self-control, let them marry. For it is better to marry than to burn with passion.
If sex before marriage was permitted, why would he encourage people to marry rather than burn?
There are a ton more verses I could list to prove my point that yes, having sex before marriage is a sin in God's eyes. Does God hate sex? Of course not! He created it for our pleasure, but like everything that's pleasurable, God put boundaries around it for our good, in order so we could enjoy it to the fullest as He intended. For example, I love donuts. I could eat donuts all day long. But should I? Food is a great creation of the Father's, but He set limits to how much we should eat during the day and what sorts of things we should eat. If we step outside of that, we get fat and sick. If we have sex outside of marriage there are other consequences such as disease, unwanted pregnancies, and broken hearts, to name a few.
If people want to have sex outside of marriage, that's their business. I won't condemn or judge them. It's their choice. God gave them the freedom to choose how to live their lives. They can either follow Him or reject Him. But PLEASE don't try to justify your behavior by twisting the Word of God to say something it doesn't say just to suit your own lustful desires.