Never satisfied

Mortification involves a struggle between what we know to be right (our convictions) and what we desire to do. This is the struggle depicted by the apostle Paul when he wrote, "For the sinful nature desires what is contrary to the spirit, and the spirit what is contrary to the sinful nature. They are in conflict with each other, so that you do not do what you want" (Galatians 5:17, NIV). The person who tends to overindulge in sweets will struggle between a conviction about the importance of self-control and the desire to eat that delicious, tempting dessert. The man who has developed a habit of undisciplined and wandering eyes will struggle between a conviction regarding purity and the desire to indulge a lustful look. Whatever our particular areas of vulnerability to sin are, mortification is going to involve struggle—often intense struggle—in those areas.

The ceaselessness of this struggle is suggested to us in Proverbs 27:20: "death and destruction are never satisfied, and neither are the eyes of man" (NIV).

Our eyes, of course, are often the gateway to our desires. But whether the appeal to our desires comes through the eye or another avenue such as the memory, our desires are never satisfied. But it is these sinful desires that must be mortified, that is, subdued and weakened in their power to entice us into sin.

It is always emotionally painful to say no to those desires, especially when they represent recurring sin patterns, because those desires run deep and strong. They cry out for fulfillment. That is why Paul used such strong language: "Put to death therefore what is earthly in you" (Colossians 3:5). (Excerpt taken from The Discipline of Grace)