As we struggle in our sin and are shackled to the bad habits we’ve tried to become released from, there are two great defences. These weapons come on us in power when we call upon them and invest in them. And with the Spirit, these are relatively easy things to do giving us miraculous results in transforming our lives through the Spirit.
For all the vices inherent in the Seven Deadly Sins, the disciplines of the Spirit (of God) supplement life with virtue toward holy living. These do, therefore, fight effectively the sins of commission (via abstinence) and the sins of omission (via engagement).
There are hence two forms of spiritual discipline:
1. Disciplines of Abstinence (requiring and honing the virtue of Prudence), and
2. Disciplines of Engagement (requiring and honing the virtue of Diligence).
Prudence and diligence are two virtues primary to self-mastery. These two are rooted and established in Proverbs’ wisdom literature and are referred to in those writings over and over again. (For an article containing thought on self-mastery read this: Not the Means; It's the End and Purpose of Life Itself: Wisdom)
These virtues (diligence and prudence) combine to provide a cogent defence against personal vice, given our basic human propensity to sin.
When the discipline of abstinence counteracts the sins of commission and the discipline of engagement counteracts the sins of omission, a chiasm occurs. In other words, we address each problem from the opposite end: a lack of prudence (i.e. sins of commission) with abstinence, and a lack of diligence (i.e. sins of omission) with engagement.
It’s a two-pronged attack on vice to the heralding of virtue. We need both approaches. In each of the further two posts I’ll provide a brief outline of what’s covered on this in Dallas Willard’s book, The Spirit of the Disciplines: Understanding How God Changes Lives, as there’s true relevance for all people here, saved and unsaved.
 Dallas Willard, The Spirit of the Disciplines: Understanding How God Changes Lives (New York, NY: HarperCollins Publishing, 1988), pp. 156-92.