“Christian maturity is not only marked by sins that have been put to death, but by a deeper personal knowledge of and intimacy with God, and a deeper commitment to his people, the church (Ephesians 4:13). Yes, sexual immorality, anger, and deceit are being put off. But something breathtaking is being put on in their place: love.”
If we boil the Christian life down to simply killing sin, we rob ourselves of the deepest hope and highest joys.
Yes, every true Christian will be killing sin. Any other version or distortion of Christianity falls short of what Christ died for. “Put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires” (Ephesians 4:22). “If you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body, you will live” (Romans 8:13). If we do not kill sin, we will die in our sin. But if we wage war against our sin, in the power of the Spirit, we prove that Christ is alive in us, and that we will never die.
Killing sin is essential to the Christian life, but it’s not the essence of the Christian life. When Christ calls us to deny ourselves, take up our cross daily, and follow him — and he does summon us to deny ourselves — he does so that we “may have life and have it abundantly” (John 10:10). What we put on is far greater than anything we put off or leave behind.
The New You
God has given us hit lists of sins to kill. For instance, Colossians 3:5, 8–9: “Put to death what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry. . . . Put them all away: anger, wrath, malice, slander, and obscene talk from your mouth. Do not lie to one another, seeing that you have put off the old self with its practices.”
We cannot follow Christ without putting off something, but that doesn’t mean following Christ is only about what we put off.
Just keep reading in Colossians 3, next verse: “ . . . and have put on the new self, which is being renewed in knowledge after the image of its creator” (Colossians 3:10). You have not only put off your old self. You have put on a new self. And your new self looks more and more like the one who created and sustains every corner of the universe. As horrible as we looked in our sin where God found us, we are now being rebuilt and refined in his spectacular image.
We find similar language in 2 Corinthians 4:16: “Though our outer self is wasting away, our inner self is being renewed day by day.” We are being made into the image of an infinitely big, perfectly holy God. That process happens painstakingly slow — one day at a time — from one precious degree of glory to another (2 Corinthians 3:18).
The Power of Knowing God
But how are we being changed? “[You] have put on the new self, which is being renewed in knowledge after the image of its creator.” What does it mean to be renewed “in knowledge”?
This is not the first mention of “knowledge” in Colossians,
We have not ceased to pray for you, asking that you may be filled with the knowledge of his will in all spiritual wisdom and understanding, so as to walk in a manner worthy of the Lord, fully pleasing to him: bearing fruit in every good work and increasing in the knowledge of God. (Colossians 1:9–10)
Putting on the new man is not something first we do, but something we know — and in particular, someone we know. Notice how knowledge is the beginning and end of this kind of spiritual growth. Knowledge equips us to walk in a manner worthy of the Lord — “so as to walk . . . ” — and we walk in a manner worthy of the Lord because we want to know him more — “increasing in the knowledge of God.”
Christian maturity is not only marked by sins that have been put to death, but by a deeper personal knowledge of and intimacy with God, and a deeper commitment to his people, the church (Ephesians 4:13). Yes, sexual immorality, anger, and deceit are being put off. But something breathtaking is being put on in their place: love. Again, Paul prays, “It is my prayer that your love may abound more and more, with knowledge and all discernment” (Philippians 1:9).