Because I am not willing to disconnect from the rest of the world, I want to take a moment to explain sexual sin in a way that is respectful, but also respects the gospel.
The reason sexual sin is wrong is because it represents the inability to be satisfied within a covenant that God designed to reflect his own image (Genesis 2:22-23). Like most things that are designed for honorable use, sex becomes sin when people look for it outside of a spouse, and ultimately, when they don’t recognize that sex is an act of worship. Sex outside of marriage reflects the same spirit that lead God’s people to worship false idols (everywhere, but especially Isaiah 57, Revelation 17).
Like getting baptized for the sake of a shower or taking communion as a meal (1st Corinthians 11:20-34), people substitute physical desires without honoring God. Like any kind of earthly desire that involves the body, sexual appetite is akin to eating, drinking, and the like (this one I learned from Neuroscience, and the mesolimbic dopamine rewards system!). And go figure: when we seek sex outside of marriage or without understanding the significance of marriage through faith, those relationships don’t accurately represent the Creator.
For one, there is no trace of permanence in casual sex/sexual sin. If two people get married, God wants them to marry one another in the same way that the Church will be united with himself: permanently (Isaiah 62:5, Matthew 5:31). With Christ as a bridegroom, God wants us to surrender our lives to him in the same all-giving, unselfish way he provides us (1st Corinthians 13:4-7). He wants us to remain fully faithful, and share the best of ourselves with our spouses, in the same way that we share the best of this life with him (http://bible.knowing-jesus.com/topics/Firstfruits). By putting him first, we put one another first. We are changed by love, and we celebrate God’s goodness by marriage. Marriage that relies on Jesus (the Bridegroom himself, who fulfilled that Divine love story) reflects God’s love in a way that redeems Adam and Eve, transforming humanity’s story of pain, waiting, and longing into beauty. Marriage is a place to be cherished, in the same rich, fat with joy life that God commissioned us to enjoy through worship. Marriage isn’t just sex, or companionship, or competing with your college roommates on who can get into an un-fulfilling union first. It’s always striving towards the truth in “true love”, and orienting your life in a way that you need Jesus to get there.
Which is why it’s worth it to wait: because marriage is an act of faith. Why would you get married apart from God’s image, if you are a Christian, feel called to marry, and want to experience his love fully? Marrying outside of Jesus and having sex outside of marriage are just not as rich as they could be.
At the same time, not all people are meant to get married. While a lot of people just assume that by being born human, they should have plenty of opportunities at sex (because it’s a “human experience”), that’s not true either. Although we have made various idols out of sex in US culture, not every person is meant to get married (1st Corinthians 7). Not all humans have the need for marriage, or desire intimacy, or need it to grow by the ways that God has called them. So many people have become sold out on the notion of sex in the place of God that they blindly assume that sex will complete them, or can bring the same kind of joy that is a worship thing, instead of simply a sex thing. By being afraid to be alone, afraid of what deciding not to get married will mean, afraid of disappointing our parents, afraid of not being good enough, or afraid of missing out, we miss the beauty of being satisfied in God alone. If you are really consumed by love for God and really in love with the promises you receive through the gospel, it is possible to live a well adjusted and happy life without the panic, single or married. While we have thousands of romantic comedies in hundreds of languages that reflect human’s desire for intimacy, if we recognized that our earthly need for intimacy was a God thing and not a sex thing, we’d be a lot happier. To be honest, sex without a spiritually solidified covenant connection is going to be just like it sounds like: earthly, un-fulfilling, based on fitting bodies together, not based on love.
I realize that the world’s definition of “love” isn’t what Christian’s acknowledge as love, and that is a good thing. Love isn’t just having a lover, but being loved permanently by an infinite God who is perfect. Being loved by a God who loved you (individually you and collectively us) so much that he sacrificed part of himself through his son Jesus so that everyone could know better. The goal here is to be satisfied, and that is entirely, infinitely possible in Christ. If we make our goal sex and call it marriage, there are going to be a lot of broken hearts.