Christians are often portrayed as killjoys who take the fun out of sex, because modern society blares the joys of an unrestrained sex life 24/7 from every media outlet imaginable. Since Christianity allows sex only under the auspices of marriage, Christians are mocked by a world which views virginity and marital fidelity with contempt, and maligned as “hating sex.”
But, Christianity, far from demeaning sex, actually celebrates sex as a joyful, beautiful act (See the Song of Solomon). In fact, it is precisely because Christianity treats sexual union with such reverence that it forbids premarital sex.
Ironically, comedian Stephen Colbert described the Christian view of sexuality in a crude but accurate manner , declaring on a recent show: “Sex isn’t two drunk strangers getting their freak on at closing time. It is the mystical union of two people inspired to create new physical life while God adds a soul in a divine an ineffably beautiful three-way.”
Of course, Colbert was mocking the Christian view of sexuality. Sex is viewed by most people in modern society as a pleasurable itch for any two consenting adults to scratch, and little else.
But sex, for Christians, is more than a mere pleasurable biological urge that can be fulfilled by any two random people. Sexual union, as understood by Christians, is a participation in the unitive mystery of God. The unity between a man and a woman reflects the unity of the Trinity. During the act of sexual union, a man gives himself completely to his woman, and the woman gives herself completely to her man. Both man and woman are completed in a joyful union – the two literally become “one flesh.” (Mark 10:8)
But outside of marriage, this joyful unity cannot be achieved. Only when a man and a woman have vowed themselves fully and completely to one another before God is such a union possible, because God must be present before two people can fully give themselves to one another. As Christ states: "What therefore God has joined together, let not man put asunder." (Mark 10:9)
Outside of marriage, sexual union is a lie. Two people say with their bodies that they love each other completely and totally – but they have not vowed fidelity to one another before God. And couple engaging in premarital sex can choose to "back" out of their love at any time through breaking up - and more often than not, do so.
The physical world reflects the material world. Every holding of hands, each embrace, every kiss passed between a man and a woman in a relationship is a sign of the love and the unity which that couple shares. Sexual union is the sign of the ultimate union between man and a woman, where they give themselves fully to one another. Premarital sex destroys that assurance, by treating that bond casually.
The results of premarital sex are predictable – shattered relationships and a rise in societal discord between men and women. Men and women learn to distrust each other, because they lie with their own bodies.
So it is not because Christians despise sexual intercourse that they forbid premarital sex. Rather, it is because they treat sexual union with incredible honor, and recognize it for the glorious act that it is.