From Of the Mortification of Sin in Believers, by John Owen
Sin doth not only still abide in us, but is still acting, still labouring to bring forth the deeds of the flesh.
He works upon our understandings, wills, consciences, and affections, agreeably to their own natures; he works in us and with us, not against us or without us; so that his assistance is an encouragement as to the facilitating of the work, and no occasion of neglect as to the work itself.
All other ways of mortification are vain, all helps leave us helpless; it must be done by the Spirit.
He that is appointed to kill an enemy, if he leave striking before the other ceases living, doth but half his work.
When a lust hath lain long in the heart, corrupting, festering, cankering, it brings the soul to a woful condition.
Consider what ways, what companies, what opportunities, what studies, what businesses, what conditions, have at any time given, or do usually give, advantages to thy distempers, and set thyself heedfully against them all.
A sin is not mortified when it is only diverted.
In such a case an ordinary course of humiliation will not do the work: whatever it be, it will by this means insinuate itself more or less into all the faculties of the soul, and habituate the affections to its company and society.