What Does the Bible Say about Sex Outside of Marriage?
What does the Bible say about sex outside of marriage? Since the law is written on the heart (Rom. 2:15), even unbelievers know something of the purpose and boundaries of sex, though they suppress this knowledge (Rom. 1:18). The pivotal factor is whether one submissively accepts the answer. Even still, skeptics of the Christian faith and those attempting to rationalize sin will often point out that the Bible doesn’t explicitly condemn nonmarital sex. Though we aren’t to answer a fool according to this folly (Prov. 26:4), Christians are to be unabashedly clear about what the Bible clearly teaches about sex.
Not without reason has Satan worked tirelessly to pervert sex. Because sex is sacred, its profaning is catastrophic. Generally, sex has been despised and abused in two primary ways: through licentious pandemonium or by a gnostical regarding of sex as taboo. For the former, the sundry prohibitions against sexual immorality are ignored. For the latter, the book of Genesis is ignored, and the Song of Songs is just downright embarrassing. Both perspectives betray a fundamental misconception and disorder of God’s design. And grasping God’s original design for sex is a sine qua non for answering the present question.
According to the first book of the Bible, man was created good. Woman, also, was created from man (Gen. 2:22) and corresponded to man (Gen. 2:18). As his counterpart (1 Cor. 11:11), woman was the divinely granted help meet (Gen. 2:18, KJV) man needed to usher creation into its intended consummation, where God and His image-bearers dwell together in harmony. This was to happen by mankind obediently carrying out the creation mandate: “Be fruitful, and multiply” (Gen. 1:22). To put it straightforwardly, God’s original design to bring His creation into its consummate state included sexual intercourse between one man and one woman, wherein sperm and egg unite to form an embryo (i.e., human). Sex is the way to be fruitful and multiply. Through this union, forged by fruitful sex, God’s kingdom is established through His vice-regent image-bearers. This is a foundational element of the Christian sexual ethic: sex, as intended by God, is good.
But God doesn’t sanction sex in every context. According to the Bible, there’s only one context in which sex is permitted. It’s only within the context of a covenant union between one man and one woman. These constraints weren’t implemented by some cantankerous Victorian-era priest. God designed sex, and God set the rules for sex. Perhaps now more than ever, the Christian sexual ethic is derided, even among church people. But the Bible’s sexual ethic isn’t nebulous. As C.S. Lewis stated, it’s “either marriage, with complete faithfulness to your partner, or else total abstinence.”
From the very beginning, the one-man-and-one-woman boundary is distinctly implied in the creation of only one woman for Adam. God didn’t create four wives for Adam, but one. The union described in Genesis 2:24 precedes the uniting sexual act: “a man shall leave his father and his mother and hold fast to his wife,” and then and only then, shall they “become one flesh.” Unwed sex is an attempt to enjoy the fruit of the marital union without the union itself. Paul addresses this in his admonition to the Corinthians:
Do you not know that your bodies are members of Christ? Shall I then take the members of Christ and make them members of a prostitute? Never! Or do you not know that he who is joined to a prostitute becomes one body with her? For, as it is written, “The two will become one flesh.” But he who is joined to the Lord becomes one spirit with him. Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. (1 Cor. 6:15–18)
“Casual sex” is a contradiction in terms. Marital acts are for the marital context alone. Paul clarifies that if one cannot control his sexual desires, his recourse isn’t to “sleep around,” but to marry (1 Cor. 7:9). This admonition would make little sense if Paul presumed that nonmarital sex was pure. As it is, we’re not to “stir up or awaken love until it pleases” (Song 2:7). The implication is that there is a time when love ought to be awakened, but not before. Hebrews warns against sexual immorality and holds forth an undefiled marriage bed as the antidote. But notice that only the marriage bed can be described as “undefiled” (Heb. 13:4). By definition, a nonmarital sexual encounter (i.e., “bed”) is defiled.
For the Christian, sex outside of marriage isn’t an option. Yet where it has regrettably transpired, a contrite heart God does not despise (Ps. 51:17), for we have an advocate with the Father, the Lord Jesus Christ, the propitiation for our sins (1 John 2:1–2). Trust Him, and sin no more (John 5:14; 8:11).