Warning gives way to rationale. Christians should avoid immoral behaviors not only because it displeases God, but also because that kind of living goes against the truth of the new life in Christ. In coming to faith, repentance means that we have “laid aside the old self with its evil practices.” This is a reprise of Paul’s earlier question, “If you have died with Christ to the elementary principles of the world, why, as if you were living in the world, do you submit yourself to decrees, such as ‘Do not handle, do not taste, do not touch…’ ”(Col 2:20-21). Fundamental to the Christian life is the death of self. There is the spiritual reality of it, and there is also the ongoing embracing of it. In dying to self, we lay aside the old behaviors and practices.

Unfortunately, at conversion we don’t instantly change everything in our outward lives. Like a child that is born into a new life outside of the womb, there is still a lot of growing to do. We need to build on the new life, or in the words of verse 9, we need to build on the laying aside of the old self and not continue to live like that anymore. The positive side of this is putting on “the new self.” The imagery is that of putting off a set of old clothes and putting on a new set. We Christians need to daily adorn ourselves with the new life, and not go back to the old (which, if you remember, is the immoral behaviors and ways of relating to people discussed in the previous verses).

But how does this kind of effort differ from the usual religious or moral effort found in all religions and ethical sensibilities? What keeps this from being simply the virtue of self-control that all civilized, educated people pursue? Well, Paul is saying that left to our selves, the “old self” will continually dominate and result in moral misbehavior, regardless of self-effort. But as believers in Jesus Christ, we are dealing with a different foundation. We operate from a different reality, a different perspective: “Therefore if anyone is in Christ, he is a new creature; the old things passed away; behold, new things have come” (2 Co 5:17). And further, God is at work renewing us continually as we grow in our knowledge of Christ. The more we know Him, the more we become like Him. How wonderful it is, then, to know that we have the mystery revealed to us that Christ is fully God (Col 1:19, 2:9), and we are complete in Him (Col 2:10). Let us, therefore, grow in our knowledge of Him.