The Bible teaches that God created humanity in His own image, designing them distinctly as male and female. Genesis 1:27 declares, “God created man in His own image, in the image of God He created him; male and female He created them.” As Thomas Adams once observed, “As God by creation made two of one, so again by marriage He made one of two.”

From the beginning, God established marriage as a covenant between one man and one woman. Genesis 2:24 affirms this divine design: “For this reason a man shall leave his father and his mother, and be joined to his wife; and they shall become one flesh.” Scripture consistently presents marriage as a lifelong union, intended for companionship, unity, and mutual commitment.

Within this covenant alone, God ordained sexual intimacy. As 1 Corinthians 7:2 instructs, “But because of immoralities, each man is to have his own wife, and each woman is to have her own husband.” Marriage, therefore, is not merely a human tradition, but a sacred institution created by God for the flourishing of both husband and wife.

The Bible teaches that sexual intimacy is designed exclusively for the covenant of marriage between a husband and wife, and it classifies all sexual activity outside that union, whether heterosexual or homosexual, as sinful. In 1 Corinthians 6:18 we are instructed, “Flee from sexual immorality. Every other sin that a person commits is outside the body, but the sexually immoral person sins against his own body.” This warning applies to both outward actions and inward desires.

While Scripture clearly defines sexual immorality as sin, it does not authorize hatred or mistreatment of those who struggle with it. The Bible recognizes that every person is born with a sinful nature and a propensity toward desires contrary to God’s commands. Because of this, believers are called to deny the desires of the flesh, pursue holiness, and strive for righteousness, regardless of what specific temptations or tendencies we face.

Colossians 3:5 instructs believers, “Therefore consider the members of your earthly body as dead to immorality, impurity, passion, evil desire, and greed, which amounts to idolatry.” In the New Testament, the Greek word most often used for sexual immorality is porneia. This term is also translated as whoredom, fornication, and even idolatry. At its core, porneia refers to the giving up or abandoning of sexual purity, and is typically applied to sexual activity outside the covenant of a biblically defined marriage.

Scripture teaches and affirms this marital covenant consistently, in the Law and Prophets of the Old Testament, in the teachings and letters of the New Testament apostles, and in the words of Jesus Himself. All three agree in defining marriage as a sacred union between a man and a woman.

Jesus affirms this clearly in Matthew 19:4–5:

“Have you not read that He who created them from the beginning made them male and female, and said, ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh’?”

God’s Word calls believers to pursue holiness by practicing complete abstinence from all sexual activity outside of marriage. Scripture is clear that sexual purity is part of God’s will for His people. In 1 Thessalonians 4:3–4, we read: “For this is the will of God, your sanctification: that you abstain from sexual immorality; that each of you know how to possess his own vessel in sanctification and honor.”

Marriage is the God-ordained covenant where sexual union is rightly expressed, rooted in love, sacrifice, and mutual honor. Ephesians 5:22–33 gives a model for this sacred relationship: wives are called to respect and support their husbands, just as the Church submits to Christ; likewise, husbands are commanded to love their wives with the same self-giving, sacrificial love that Christ showed His Church. Scripture teaches that in marriage, the two become one flesh, bound together in unity, purity, and devotion, reflecting the relationship between Christ and His people.