Chapter 13 is the concluding chapter of the book of Hebrews and ends with a series of final exhortations to Christians. Verse 4 says, “Marriage is to be held in honor among all, and the marriage bed is to be undefiled; for fornicators and adulterers God will judge” (NASB). The Greek word translated “undefiled” is only used in this exact form four times in the New Testament, and it means “uncontaminated” or “set apart.” Hebrews 7:26 uses this word to describe Jesus Christ, our high priest, and James 1:27 says that “undefiled” religion is that which helps widows and orphans and remains unstained by the world.
The marriage bed is to be kept pure or undefiled. In other words, the sexual intimacy shared between a husband and wife is to be reserved for that couple alone. God created the sexual union to be between a husband and a wife. Period. Only. No other use of sexuality is ever condoned in Scripture. To abuse or misuse God’s gift of sex is to defile the marriage bed.
A marriage bed can be defiled in several ways:
1. Fornication. When two unmarried people engage in sexual intercourse, they are defiling God’s good gift of sex. Those who have not vowed themselves to each other in a binding lifetime union have no right to exploit the culmination of such a vow. Sex was designed to be the final act of consecration when a couple pledge their lives to each other in a sacred covenant. All forms of sexuality outside a marriage union are bringing dishonor to the honorable institution of marriage (1 Corinthians 6:18).
2. Adultery. When one or both parties in a sexual union are married to someone else, God calls their sexual acts adultery. Adultery was punishable by death under God’s Old Covenant with Israel (Deuteronomy 22:22; Leviticus 20:10). Even though we no longer live under that covenant, adultery is still high on God’s list of moral evils (Matthew 5:28, 32) and is always named as a sin that keeps unrepentant offenders from inheriting the kingdom of God (Galatians 5:19; 1 Corinthians 6:9).
3. Homosexuality. Another defilement of the marriage bed is the perversion of men having sex with men or women with women. Despite our world’s current embrace of homosexual practice, this vile act has never been and will never be sanctioned or blessed by God. Homosexuality is a distortion of God’s gift of physical unity between husband and wife and is the only sexual activity labeled an abomination (Leviticus 20:13). The prohibition against homosexuality carries right into the New Covenant, as it is listed with those sins that keep the unrepentant out of the kingdom of God (1 Corinthians 6:9; 1 Timothy 1:9–10; Jude 1:7).
4. Prostitution. Proverbs 7 gives a detailed look at the destruction that comes upon a young man who allows himself to be seduced by a harlot. The sin of harlotry is often used as a metaphor for unfaithful Israel (Hosea 4:15; Jeremiah 3:8; Judges 8:33). Christians are warned to avoid such immorality because of the sacredness of the marriage bed (1 Corinthians 6:15–16; Ephesians 5:3).
5. Pornography. Using pornography for sexual gratification is a more modern way to defile the marriage bed. Pornographic books, videos, sexting, and the use of other sexually explicit materials also defile the sanctity of the sexual union between a man and wife. Porn has the effect of bringing strangers into the bedroom, even if only through the eyes. Jesus warned that lust associated with looking at a woman is equivalent to adultery before God (Matthew 5:28). Pornography has elevated sexual lust to an art form, but it is still corrupting to the heart and a sinful defiling of the sexual act.
God created human beings to be pure in body and spirit. Sexual union between a husband and wife was a part of that purity (Genesis 2:24–25). When Adam and Eve sinned, sexuality was tainted along with everything else. Jesus purchased the power to reclaim that purity through His sacrificial death on the cross (2 Corinthians 5:21). No sin, including sexual immorality, is too great for the power of that atoning death and resurrection to pardon. Even though we may have defiled the marriage bed in many ways, God can restore sexual purity and holiness when we repent and commit our lives to following Him (Psalm 51:7; 1 John 1:7).