Thanks for the question. As is so often the case with apologetics, it’s important to point to our unvoiced assumptions here. One practical way to define culture is to say that it’s “just the way things are.” This is how many highly destructive ideas and patterns of behavior fly under the radar and just seem to make sense, even to Christians. With regard to sexual immorality, the cultural assumption is that sex is a human institution and that it’s therefore under our authority. Consequently, any limitations we place on it are purely legal. For this reason, most of our serious relational and sexual conflicts, from divorce to marriage debates, don’t look to the church for guidance, but instead turn to the law. In this sense, we often view marriage as contractual, rather than covenantal. It’s difficult to emphasize just how much damage this has done to us. It hardly needs to be said that Christians (especially in North America) have fallen into this trap.
Another background assumption is that sex is the most profound form of intimacy and that it’s a needed ingredient in human fulfillment. If Christianity is true, however, this cannot be the case. As my colleague Sam Alberry points out, to say that sex is needed for a full expression of one’s humanity is to call Christ subhuman. Rather, we need a real relationship with our Maker if we want to experience the fullness of our humanity.
But we don’t just view sex as something we own. We also take an increasingly casual approach to it. The theologian Miroslav Volf points out that one of the most destructive habits of mind in our world today involves the divorce of pleasure from meaning. Pornography, for instance, presents a vision of sex devoid of all deeper meaning. Instead, human beings are reduced to little more than bodies in motion—objects for self-gratification. This assumption has done inestimable harm to our relationships, and it’s also fed one of today’s most vile forms of organized crime: the sex trafficking industry.
So, I think we can start to address this problem by pointing to the Lord as the author of marriage. Marriage is covenantal, not contractual. You may get married because you love someone, but after that, you love them because you’re married. If Christ is indeed the author of marriage, then his rules ought to guide our practice. We also need to recover Scripture’s high view of sex, rather than the desiccated picture offered by our culture. I’m reminded of a powerful reflection from Wendell Berry. Pointing to the fact that pornography usually emphasizes the body to the exclusion of the face, he says “the countenance is both physical and spiritual. There is much testimony to this in the poetic tradition and elsewhere. Looking into one another’s eyes, lovers recognize their encounter as a meeting not merely of two bodies but of two living souls. In one another’s eyes, moreover, they see themselves reflected not narcissistically but as singular beings, separate and small, far inferior to the creature that they together make.”
But we’ll need to do much more than offer sound arguments; we’ll need to lead by example. For those of us who are married, we need to model the vision of marriage that Christ commends to us. For those of us who are single, we need to reject the cultural lie that sexual intimacy is a needed ingredient in being a fulfilled human being. The needed ingredient is instead a vital relationship with the Living God.