The key to much of what I've been talking about is seeing the continuity between how we get born again and how we become more like Christ. The Gospel is absolutely central in both our justification and in our sanctification. A lot of people treat the Gospel as if it's the message that we hear to get justified, but once we're saved we go on to something else for our sanctification. But the means of both are the same! The way we get justified is the same way we progress in sanctification.
This is what I mean: Having been awakened to life by the effectual grace called the new birth, and having been given eyes to see, in the moment of conversion we saw Jesus as infinitely more precious and infinitely more desirable than our sin. And we received Him as the treasure of our lives, putting our trust in Him to cleanse us from all our unrighteousness and to commend us to God on the basis of His righteousness alone. Nothing other than seeing Jesus caused that to happen. That's why Paul talks about our conversion as coming by the "light of the gospel of the glory of Christ" (2Cor 4:4).
What I’m saying to you is that just a few verses earlier, 2 Corinthians 3:18 teaches that we are sanctified – matured, grown, made more holy, transformed into the image of Christ – by the very same thing: by "beholding the glory of the Lord" (2Cor 3:18). As Christians, when sin presents itself to us and tempts us to believe its lies, we simply look to Jesus and see Him for who He is! And because the glory and the satisfaction of sin doesn’t hold a candle, we prefer Jesus, and so delight in obeying Him! This is God-glorifying obedience: when the worth of Christ is magnified by His people preferring Him over anything else in the world!
So the point is: As it is the seeing and savoring of the glory of God in Christ alone that saves us, it is the seeing and savoring of the glory of God in Christ alone that sanctifies us. So fight the fight of holiness in the Christian life on the level of spiritual sight. When you're tempted, fight with all your might to see your Savior in all His glory. It is the glory of the Lord that will transform you.
beholding as in a mirror the glory of the Lord,
are being transformed into the same image
from glory to glory.
1. The Theology of the New Birth
1.1. Man's Spiritual Death (Total Depravity)
1.2. The Dead Cannot See
1.3. The Wind Blows Where it Wishes: The Freedom of God and Irresistible Grace
1.4. Regeneration and Faith: Temporally Simultaneous but Logically Distinct