You shall not covet thy neighbor’s wife.

The ninth commandment is defined as a warning against lust and carnal concupiscence (CCC 2529). As part of the Decalogue, it serves as a path of life intended to free humanity from the slavery of sin (Deuteronomy 5:29-30, CCC 2058). This commandment is not an isolated rule but is part of a covenant between God and His people, sealed by God’s own presence and the revelation of His holy will and nature (Exodus 19-20, CCC 2059-2060).

In Christian practice, the struggle against carnal lust requires the purification of the heart. This is achieved through the practice of chastity, prayer, and maintaining purity of intention and vision (CCC 2532). Such purity is significant because it enables the believer to see God and all things according to His will (CCC 2531). Furthermore, purity of heart necessitates the practice of modesty, which serves to protect the intimate center of the person (CCC 2533). While these obligations are grave, God provides the grace necessary to make the fulfillment of His commands possible (CCC 2082).