When God creates humans, he pronounces them “very good/beautiful” (Gen. 1:31). They are designed to be magnificent visual displays of God’s character (1:26
27). Human sexuality originally is set in a context of overwhelming beauty. God’s first command is to reproduce and extend this paradise throughout the earth (1:28). Human sexuality is not simply a mechanism for reproduction. From the outset it has been about completion, without which there is loneliness (2:18).
Although the Bible does not define the distinctives of masculinity and femininity in any detail, it does defend that there are distinctions between the genders. Behaviors that confuse the genders are explicitly condemned (Deut. 22:5; 1 Cor. 6:9; 11:4–16).
Homosexual intercourse (Lev. 18:22; 20:13; Rom. 1:24–27; 1 Cor. 6:9; 1 Tim. 1:10) and intercourse with an animal (Exod. 22:19; Lev. 18:23; 20:15–16; Deut. 27:21) are violations of God’s created order.
Although damaged by sin, marriage continues to be the ultimate human relationship involving intimacy, privacy, and liberty. Marriage is defined by a covenant—a contract witnessed and enforceable, not just a promise made in private. The couple separate from their parents to become “one flesh” (Gen. 2:24).
Once the marriage contract is agreed upon, the couple are married. They cannot consummate the marriage until the economic commitments of the contract have been delivered (Matt. 1:18; 25:1–13). This is celebrated with a feast. Jesus uses this custom as an analogy for his departure and return (John 14:1–3).
Paul commands husbands to love their wives (Eph. 5:25–33; cf. Gen. 24:67; 29:20; 1 Sam. 1:5; Eccles. 9:9; Song 8:6–7). Nowhere in the Bible is a wife commanded to love her husband, though older women should teach younger women to do so (Titus 2:3–4). Love is the husband’s responsibility. Love is a command that can be obeyed, not just a pleasurable feeling over which one has no control. The model of husbandly love is Jesus laying down his life for his people.
The ecstasy of making love is celebrated in the erotic Song of Songs, which holds out the hope of such marital delight even now. The axiom of marriage is a righteous jealousy (cf. Exod. 20:5; 34:14; Num. 5:14, 30; Prov. 6:34).
The first year of marriage is especially important and is protected by exemption from military service (Deut. 20:7; 24:5).
When a man dies without a male heir, his widow’s possession of that part of the family estate can result in her marrying a man from another family and so alienating that land. This can be resolved either by the injustice of eviction or by the device of levirate marriage. The nearest male relative of the deceased husband marries the widow, and their son then inherits the deceased husband’s name and title to the land (Deut. 25:5–10; cf. Gen. 38; Ruth).
Concubines are wives from poor families, slaves, or captives, and their marriages are protected (Exod. 21:7–9; Deut. 21:11–14).
Rape of a married woman constitutes adultery by the rapist, not the victim. Consensual sex with a married woman is adultery by both parties. Rape of a single woman is treated as fornication, with no blame attached to the woman. Her father has the option of letting her marry the man or receiving significant financial compensation (Exod. 22:16–17; Deut. 22:23–27). Her father has the right to take the money and refuse the marriage. To falsely accuse a woman of adultery is a crime (Deut. 22:13–21).
Prostitution is an extreme form of adultery or fornication and totally forbidden (Lev. 19:29; Deut. 23:17). Under the new covenant, this warning is heightened by the reality of the gift of the Holy Spirit transforming each believer into the temple of the Lord (1 Cor. 6:15–20).
Originally, marriage between siblings is implied (Gen. 4:17, 26; 5:4). Abram married his half sister, Sarai (Gen. 20:12; cf. Gen. 11:29; Num. 26:59). The Mosaic covenant at Sinai bans marriage to blood relationships closer than first cousins and to in-laws (Lev. 18:6–30; cf. 2 Sam. 13; 1 Cor. 5:1).
Polygamy occurs soon after the fall (Gen. 4:19–24). It is never explicitly forbidden in the Bible, but it is managed by OT law so as to restrain further injustice and damage. It is always seen as less than satisfactory (cf. Gen. 29–30; 1 Sam. 1:6; 2 Sam. 13; 1 Kings 1–2; 11). In the NT, monogamy is mandatory for those who would lead the church (1 Tim. 3:2, 12; Titus 1:6).