Where Sin Is Hatched

No one ever “falls” into adultery. The adulterer’s heart is always shaped and prepared by lustful thoughts before the actual deed occurs. Likewise, the heart of the thief is bent by covetousness. And murder is the product of anger and hatred. All sin is first incubated in the mind.

Jesus taught this truth to His disciples: “The things that proceed out of the mouth come from the heart, and those defile the man. For out of the heart come evil thoughts, murders, adulteries, fornications, thefts, false witness, slanders. These are the things which defile the man; but to eat with unwashed hands does not defile the man” (Matthew 15:18-20, emphasis added).

Jesus was teaching that the real point of the Mosaic law was the moral truth embodied in the external ceremonial requirements. He downplayed the symbolic aspects of washing and abstaining from what is legally declared unclean. Instead He emphasized the moral requirement of the law.

 Defilement, He suggested, is not primarily a ceremonial or external problem; what is truly defiling in the spiritual sense is the wickedness that emanates from the heart. In Scripture, “the heart” is the seat of the whole person—mind imagination, affections, and will. “Heart” is often used as a synonym for “mind.” In these verses, therefore, our Lord was condemning the wickedness of an impure thought life.

Again and again, Christ rebuked the Pharisees for their fastidious observance of the external, ceremonial law and their wanton neglect of the law’s moral requirements. They were utterly preoccupied with appearing to be righteous. Yet they were willing to tolerate the grossest sins of the heart. They thought no one else could ever discover what was really inside them. But our Lord knew what was in their hearts (Matthew 9:4; 12:25). He compared them to elegant crypts, beautiful on the outside but full of defilement and death on the inside.  Continue at John MacArthur