Put off your old self, which belongs to your former manner of life and is corrupt through deceitful desires, and to be renewed in the spirit of your minds, and to put on the new self, created after the likeness of God in true righteousness and holiness.
Christianity is not like any other school. It is not a moral self-improvement course. You don’t just sign up and work hard to change yourself. That’s the school of legalism, not the school of grace.
In the school of Christ change comes in a totally different way, by grace through faith, so that the schoolmaster gets all the glory, not the students. That’s why Paul describes the coursework with such strange language. It’s like nothing you have experienced anywhere before entering this school.
In the school of grace, your new clothes are created (Ephesians 4:24). God creates the new person that we must put on. The new person is the bundle of attitudes and emotions and practices that make up the new you. That is what verse 24 says God creates. He creates the new you. The bundle of attitudes and emotions and practices are created after his own likeness in righteousness and holiness, the course catalogue says.
This is totally unlike any other school in the world. We are given the assignment to become holy; but then we are told that God creates our holiness. This is a very strange school. Look at Ephesians 2:10 for one of the strangest sentences of all in the course description:
We are his workmanship, created in Christ Jesus for good works, which God prepared beforehand, that we should walk in them.
How mindboggling is this? We are God’s workmanship, God’s creation. And not only that, the works that we are assigned to do — he has already prepared those, too! Who is working in this school, anyway?!
Do you see why Paul can’t just say, “Okay, you’re a Christian now; get rid of your bad habits and get some good ones”? That is the curriculum in the school of legalism: God saved you, now improve yourself. No! In the school of grace, God creates the new person — and that includes all the new attitudes and emotions and practices that we are supposed to put on.
When your mind is filled with Christ’s love and with all the fullness of God, then the spirit of your mind is renewed and freed from the deceit of the world. And out of that renewed mind comes new attitudes and emotions and practices, and they clothe you with righteousness and holiness. And this new person that you become is indeed the work of God himself, and to him belongs all the glory forever and ever.