In chapter 6 of The Mortification of Sin, John Owen gives three general descriptions of what the mortification of sin is .This follows the 5 general descriptions in chapter 5 of what mortifying a sin is not. (I wonder if the book should be entitled The Mortifying of Sin as the continual nature of the work of mortification is often repeated.) Owen is widely circling the prey. These general principles will give way to general directions in the next chapter which will give way to particular directions in still future chapters.
Since every sin is the result of a habitual lust, such lust and sin must be fought habitually. The only reason one particular sin does not overcome a man is because he is related to sin like a your old with five dollars in a candy store- there is just so much to choose from. Nevertheless, his general inclination is toward himself and sin. And eventually, he will find his favorite candy. Mortifying sin is attacking the roots of sin and the strengths of its habituating nature. Sin with violence, earnestness, and frequency rises up to provoke, entice, and disquiet the soul. It must be confronted at the foundational and fundamental levels.
The strongest temptations and lusts seek hospitable ground to grow in. Lust and sin find out where a man is naturally weakest, and there take root. Lust “falls in with the natural constitution and temper, with a suitable course of life, with occasions.” Sin attacks and latches on where are most prone to give in.
Just as men have many different constitutions and tempers, so does sin. Some sins are obvious, open, and visible; e.g. sexual sins. Some sins primarily focus internally on the destruction of the soul; e.g. worldliness. A man might outwardly appear well, serene, and holy; but sin might be as dominant in his life as in the most flamboyant of sodomites.
Such sin must be weakened at the habit. The life and vigor animating sin must be cut off. Sin must be attacked continuously at the root. A man can pick the bitter fruit off a tree as long as he wants. As long as the root remains, the fruit will be rotten. As long as you are content to focus on the “appearing lust” of sin but leave the “principle and root untouched” little to no progress will be made in mortifying sin.
Turning to myself, as long as my goal is only to stop swearing when I am alone in the car or when I think no one can hear me, my soul will remain profane. I am not really going to put profanity to death until I get to the death-giving roots of my profanity.
Secondly, mortification is always mortifying. Man must be under sure conviction of the sinfulness of sin. Man must be convinced of the danger of sin; the peril of sin; the end of sin. As long as man thinks lightly of sin, he will not take up arms against it. Under the conviction of the sinfulness of sin, man will be eager to do battle with it.
The one doing battle with sin, will wage a wise warfare. A crucial aspect of this is studying the enemy. What are the “counsels and designs” of my lusts? What are the ends of my sin? “How and by what means” has temptation formerly prevailed in my life? What are sin’s ways and progress in my life? What are its advantages? How has it triumphed? The wise man finds out “the subtleties, policies and depths of any indwelling sin.”
When this is done, one is ready to load sin daily with all the things that are “grievous, killing, and destructive to it.” The wise soldier is tenacious and never stops fighting, even when the enemy is quiet. The one fighting against sin is always seeking to give it “new wounds, new blows, every day.”
Thirdly, mortifying does result in mortification! The one fighting against sin does actually gain victory over sin. Not victory in the sense that sin never bothers him again. But victory in the sense that sin is immediately confronted and successfully overcome whenever lust stirs temptations.
Now I saw when a man comes to this state and condition that lust is weakened in the root and principle, that its motions and actions are fewer and weaker than formerly, so that they are not able to hinder his duty nor interrupt his peace; when he can, in a quiet, sedate frame of spirit, find out and fight against sin, and have success against it; then sin is mortified in some considerable measure, and notwithstanding all its opposition, a man may have peace with God all his days.
And this victory all comes from man’s wise warfare? No. The deep-rooted lusts of sins are replaced by contrary “graces of the Spirit.” Pride is weakened by the Spirit’s gift of humility; passion by patience; uncleanness by purity; worldliness by heavenly-mindedness. Daily fighting against sin is only by the promptness and vigor of the new man created by the Spirit using all the comforts and weapons He provides. This is the victory granted by the new covenant of grace: the covenant in which God promises to place is Spirit in all His people.