Deuteronomy 5:18

Neither shalt thou commit adultery.

Deuteronomy 5:18 (KJV)

Context

Moses speaks these words to Israel on the plains of Moab, just before they enter the Promised Land. He restates the Ten Commandments to a new generation, reminding them of God’s covenant and their calling to be a holy people. This is the seventh commandment, a direct prohibition against sexual immorality.

Meaning

The command forbids adultery, meaning any sexual relationship outside the marriage covenant. Adultery is not merely a private sin; it breaks the sacred bond between husband and wife and damages the trust and stability of the family. In Scripture, marriage is a divine institution, established by God from the beginning (Genesis 2:24). Therefore, violating it is an offense against both one’s spouse and God. The command calls God’s people to holiness and purity, reflecting their set-apart status. It is a positive safeguard for the marriage bond, which is a picture of God’s covenant relationship with His people.

Biblical connections

This command is not only about outward behavior. Jesus taught that even lustful thoughts are a form of adultery in the heart (Matthew 5:27-28), calling for purity of heart, not just correct actions. The Bible also uses marriage as a picture of God’s faithful relationship with His people. When Israel turned to idols, the prophets called it spiritual adultery. Thus, faithfulness in marriage reflects faithfulness to God. The marriage bond is a safeguard for the family and the broader community. The New Testament teaching of Jesus expands on this, explaining that the command also addresses the inner disposition, warning against lustful intent, not merely the outward act.

Application

Believers are called to honor the marriage covenant and to live with faithfulness and purity. This means guarding both actions and thoughts, and cultivating love, trust, and respect within marriage. The commandment is not merely a restriction but a positive safeguard for the family and the community. It reminds us that our bodies and relationships belong to God and should reflect His holy character. Faithfulness in marriage is a matter of the heart, requiring purity of thought and desire. This spiritual application reveals that faithfulness in marriage is a matter of the heart, requiring purity of thought and desire.

Reflection

Consider the seriousness of this command and the grace God offers. Adultery brings pain and brokenness, but God’s forgiveness is available through repentance. Let this commandment lead you to examine your heart and to commit yourself to honoring God in your relationships. True obedience flows from a heart transformed by God’s love, not from mere rule-keeping. Honor God by honoring the marriage covenant in every area of life.