The gospel aids our pursuit of holiness by telling us the truth about who we are.  Certain sins become more difficult when we understand our new position in Christ.  If we heirs to the whole world, why should we envy?  If we are God’s treasured possession, why be jealous?  If God is our Father, why be afraid?  If we are dead to sin, why live in it?  If we’ve been raised with Christ, why continue in our old sinful ways?  If we are seated in the heavenly places, why act like the devil of hell?  If we are loved with an everlasting love, why are we trying to prove our worth to the world?  If Christ is all in all, why am I so preoccupied with myself?

– Kevin DeYoung in The Hole in Our Holiness

The same Spirit who was present at creation and caused you to be born again is at work to empower your inner person (that is, your will or heart) so that you might resist sins you couldn’t resist before and do the good things which would otherwise be impossible.  Defeatist Christians who do not fight against sins because they figure they were “born this way” or “will never change” or “don’t have enough faith” are not being humble.  They dishonor the Holy Spirit who strengthens us with supernatural power.
– Kevin DeYoung in The Hole in our Holiness