As a man nailed to the cross; he first struggles, and strives, and cries out with great strength and might, but, as his blood and spirits waste, his strivings are faint and seldom, his cries low and hoarse, scarce to be heard;—when a man first sets on a lust or distemper, to deal with it, it struggles with great violence to break loose; it cries with earnestness and impatience to be satisfied and relieved; but when 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 have sometimes a dying pang, that makes an appearance of great vigour and strength, but it is quickly over, especially if it be kept from considerable success. This the apostle describes, as in the whole chapter, so especially, Rom. 6:6.
“Sin,” saith he, “is crucified; it is fastened to the cross.” To what end? “That the body of death may be destroyed,” the power of sin weakened and abolished by little and little, that “henceforth we should not serve sin;” that is, that sin might not incline, impel us with such efficacy as to make us servants to it, as it hath done heretofore.

John Owen, On Mortification, Works 6:30