What is adultery?

from the old testament

• God instituted marriage when He first created Eve and gave her to Adam (Genesis 2:24). His intention was that, within wedlock, men and women would procreate and fill the earth (Genesis 1:28) and that such intimacy would be exclusive to the marriage relationship of one man and one woman. Every deviation that violates the sanctity of marriage is adultery.
• God Himself is a faithful God and sets the background for His hatred of adultery. For example, Deuteronomy 7:9 reads, “Know therefore that the LORD your God is God, the faithful God who keeps covenant and steadfast love with those who love him and keep his commandments, to a thousand generations.” Marriage is a covenant between a man and a woman, and just like God keeps His commandments, He expects us to keep ours. Because it is an expression of unfaithfulness that directly contradicts God’s nature, adultery was included among God’s Ten Commandments, which summarize the rest of the Law (Exodus 20:14).
• Additionally, it came with the severe penalty of death. For example, the Law said, “If a man commits adultery with the wife of his neighbor, both the adulterer and the adulteress shall surely be put to death” (Leviticus 20:10). The punishment was severe to match the crime.  Given its destructive nature, it is said to flow from the heart of a fool (Proverbs 6:32).
• Scripture also uses adultery in a figurative sense to explain Israel’s unfaithfulness to God. Like an adulterer breaks his marriage covenant with his spouse, Israel regularly broke her covenant with God. To illustrate their unfaithfulness, God had the prophet Hosea marry an adulteress to experience and illustrate the pain God felt. God told him, “Go again, love a woman who is loved by another man and is an adulteress, even as the LORD loves the children of Israel, though they turn to other gods and love cakes of raisins” (Hosea 3:1; cf. Ezekiel 16:30–34).

from the new testament

• In Jesus’ day, the Jews viewed adultery as the specific violation of a man or woman having sexual relations with someone who was not their spouse. However, Jesus corrected their understanding, saying that adultery begins the moment one spouse lusts for someone other than their spouse. He said, “You have heard that it was said, ‘You shall not commit adultery.’ But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart” (Matthew 5:27–28). This is also adultery because the desire to sin is there even if the opportunity to fulfill the sin does not arise.
• Adultery is strongly condemned. The author of Hebrews said, “Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous” (Hebrews 13:4). Because adultery breaks the marriage covenant and demonstrates unfaithfulness in contrast to God’s faithfulness, He holds adulterers accountable for their sin.
• Marriage is intended to be lifelong. The Jews questioned him about divorce, effectively looking for a way out of marriage, but Jesus explained that God gave them divorce because they were unfaithful, not because He approved of it (Matthew 19:3–9). Jesus said, “I say to you: whoever divorces his wife, except for sexual immorality, and marries another, commits adultery” (Matthew 19:9). While we learn more about the possibilities of divorce elsewhere (see 1 Corinthians 7), Jesus’ point was God intended a man and woman to be bound forever and divorce and thus subsequent marriage breaks that covenant and is adultery as well even if no one is cheating, in a technical sense, on a current spouse.
• Marriage was so vitally important from the beginning because it was intended to illustrate Christ’s relationship with the church. Paul said, “Wives, submit to your own husbands, as to the Lord. For the husband is the head of the wife even as Christ is the head of the church, his body, and is himself its Savior. Now as the church submits to Christ, so also wives should submit in everything to their husbands” (Ephesians 5:22–24). Faithfulness within marriage illustrates Christ’s faithfulness and loving care of His body, the church.
• In contrast, adultery perverts the church and God’s good design for marriage and human flourishing. It is therefore listed among the works of the flesh (e.g., Galatians 5:19).

implications for today

We try to walk a fine line, getting tastes of sexual sin without actually sinning by looking, not touching. However, even the “taste” in our hearts is sin, and lust for another is adultery. Adultery is a sexual craving for what is not ours, even if we don’t actually take a bite of that forbidden fruit.

While there are clearly avenues that inflame lust, such as pornographic websites, Jesus spoke about the danger in the everyday temptations that surround us. For example, the well-known adage, “sex sells,” is based on the idea that using images of beautiful women will draw our attention. Similarly, walking down the road inevitably brings us past someone wearing sexually enticing clothes. And even with those who aren’t intending to be appealing, a brief touch or eye contact can start our sinful heart considering, “what if…” If we go too far in our minds, we move beyond God-honoring attraction into lust.

We are surrounded by the temptation to commit adultery in our hearts. How do we succeed against such odds?

First, we must commit not to give a second look (Job 31:1). When temptation arises, if we have not already committed to looking away, we will likely look. Second, we need wisdom about where we go. Men and women can dress provocatively everywhere, but some locations are more permissive. We should avoid places that will only tempt us. Third, we need God’s strength. He made sex powerful, a good gift between husbands and wives. But that strength quickly overpowers sinners. As sinners, our flesh is against us (Galatians 5:17). This is why Jesus taught His disciples to pray, “lead us not into temptation” (Luke 11:4). Jesus didn’t mean that God tempts us (cf. James 1:13), but that He will protect us. Whether that’s helping us to avoid sexual temptation or to get through it, He provides a way of escape (1 Corinthians 10:13).