“The first thing in mortification is the weakening of the habit of sin or lust, so that it shall not, with that violence, earnestness and frequency, rise up and conceive, provoke, entice, and disquiet as it naturally has a tendency to do (James 1:14-15). This is called ‘crucifying the flesh with its passions and desires’ (Galatians 5:24). We seek to take away that about it which gives it strength and power. We aim at the killing of the body of death ‘day by day’ (see 2 Corinthians 4:16).
When a man is nailed to a cross, he at first struggles, strives, and cries out with great strength and might; but as his blood and spirits waste, his strivings are faint and seldom, his cries hoarse, and scarce to be heard. So when a man first determines to conquer a lust or sin, and to deal with it in earnest, it struggles with great violence to break loose; it cries with earnestness and impatience to be satisfied and relieved. By mortification, the blood and spirits of it are let out, it moves seldom and faintly, cries sparingly, and is scarce heard in the heart; it may sometimes have a dying pang that makes an appearance of great vigor and strength, but it is quickly over, especially if it kept from considerable success.
– John Owen, The Mortification of Sin, p.34-35