5.3.10.2 Covetousness–the cause of sin

The core of the Ninth and Tenth Commandments is the statement: "You shall not covet ..." It does not prohibit each and every form of human desire, only the sinful lust after the wife or property of one's neighbour. Such desire–like breaches of many other commandments–violates the commandment to love one's neighbour (Romans 13: 9).

Since the beginning of time, Satan has tried to entice mankind to sin by awakening desire and lust for forbidden things (Genesis 3: 6). Adam and Eve succumbed to this desire and fell into sin through their disobedience to God's commandment. The consequences are described in James 1: 15: "Then, when desire has conceived, it gives birth to sin; and sin, when it is full-grown, brings forth death."

Covetousness–understood as sinful craving–originates within a person. It causes unclean thoughts to arise. If it is not restrained, this sinful thought will be transformed into a deed. This becomes clear in the words of the Son of God: "For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, blasphemies" (Matthew 15: 19).

The Ninth and the Tenth Commandments assign man the task of watching over the purity of their hearts. This includes the endeavour to reject any temptation to commit sin.