Is adultery a sin according to the Bible?

Definition and Key Terms

Adultery, in the context of the Bible, is understood as engaging in sexual relations with someone who is not one’s spouse. The prohibition against adultery is explicitly stated in numerous passages and is consistently presented as a violation of both God’s moral law and the sacred covenant of marriage. The Hebrew term often rendered “adultery” in the Old Testament is “na’aph,” while the Greek term in the New Testament is “moicheia.”

Old Testament Foundations

The earliest explicit reference to adultery being forbidden is found in the Ten Commandments:

• “You shall not commit adultery.” (Exodus 20:14)

This commandment is central to the moral law given through Moses. Its seriousness is further emphasized in Leviticus, where it is listed among other grave transgressions detrimental to community and covenant:

• “If a man commits adultery with another man’s wife…both the adulterer and the adulteress must surely be put to death.” (Leviticus 20:10)

While the prescribed penalties in the Old Testament were severe, they underscored that marriage was—and remains—an institution ordained by God. Early manuscripts, including portions of the Dead Sea Scrolls, contain these commandments, revealing a strong textual consistency in preserving this moral directive across centuries (e.g., 4QDeutn preserving parallel content).

New Testament Teachings

1. Jesus’ Reinforcement of the Command

Jesus reaffirms the gravity of adultery, making it clear that this sin extends even to the realm of thought:

• “You have heard that it was said, ‘Do not commit adultery.’ But I tell you that anyone who looks at a woman to lust after her has already committed adultery with her in his heart.” (Matthew 5:27–28)

In this passage, Jesus intensifies the moral standard. Adultery is shown not merely as an external act but as a violation that begins within the heart.

2. Paul’s Epistles

The apostle Paul consistently lists adultery and sexual immorality among the sins that believers must avoid:

• “Neither the sexually immoral, nor idolaters, nor adulterers, nor men who submit to or perform homosexual acts…will inherit the kingdom of God.” (1 Corinthians 6:9–10)

By situating adultery alongside other serious sins, Paul underscores that it breaches God’s design for marriage and community holiness.

Consequences and Moral Implications

Biblical texts present adultery as harmful on multiple levels:

1. Relational Damage

It breaches the covenant bond of marriage, creating emotional and spiritual pain that disrupts families and communities.

2. Covenantal Violation

Marriage is portrayed throughout Scripture as a reflection of God’s faithful relationship with His people (cf. Hosea 2:19–20). Adultery symbolizes unfaithfulness, tarnishing this divine-human imagery.

3. Community and Societal Impact

In biblical times, stable family units were foundational to Israel’s societal well-being. Adultery undermined social order, illustrating why the Old Testament speaks out against it so decisively.

Adultery as a Symbol of Unfaithfulness

Beyond marital relationships, the prophets often employ language describing Israel’s idolatry as spiritual adultery:

• “For your mother has been unfaithful; she who conceived you has acted shamefully…” (Hosea 2:5)

In these instances, “adultery” symbolizes a deeper betrayal—turning away from God and forging alliances or devotions that violate covenant fidelity. The consistency with which Scriptures use this imagery underlines the seriousness of adultery, both literal and figurative.

Biblical Teaching on Forgiveness and Restoration

1. Divine Mercy

Despite the severity of adultery, the Bible records instances of redemption. King David famously committed adultery (2 Samuel 11) yet found restoration through genuine repentance. Psalm 51 provides a heartfelt portrayal of that repentance.

2. Encounters with Jesus

A prominent New Testament example is Jesus’ interaction with a woman caught in adultery (John 8:1–11). Though some early manuscripts reflect variations in this passage, the overall scriptural testimony affirms a theme of forgiveness. Jesus does not condone the sin, but He extends mercy: “Neither do I condemn you. Go now and sin no more.” (John 8:11)

These narratives point to the possibility of redemption without diminishing the serious nature of the offense.

Archaeological and Manuscript Consistency

Numerous ancient manuscript traditions—such as the Masoretic Text of the Hebrew Scriptures and early New Testament papyri—demonstrate a remarkable consistency in passages that condemn adultery and uphold marital fidelity. Discoveries like the Dead Sea Scrolls at Qumran have bolstered confidence that commands such as “You shall not commit adultery” have been preserved accurately through millennia.

Practical and Behavioral Perspectives

Adultery, beyond its scriptural implications, carries clear psychological and social repercussions. Researchers and counselors recognize the deep emotional trauma caused by a marital betrayal, echoing the biblical worldview that speaks against such breaches of trust. By warning believers against adultery, the Bible aligns with principles of relational health and personal well-being.

Conclusion

According to the Bible, adultery is unanimously presented as a sin and a grievous violation of God’s design for marriage. From the Old Testament commandments through the New Testament teachings of Jesus and Paul, it is portrayed as harmful both to individuals and communities. Yet alongside the condemnation of adultery stands the consistent biblical message that repentance and forgiveness remain available.

Scripture’s strong stance and the preservation of these teachings across centuries—strengthened by manuscript evidence and consistent theological witness—underscore the enduring principle: adultery is a sin, commands against it are preserved, and God offers a path to restoration for those who seek it.