In the new birth, God recreates man in his original, sinlessly pure state. John presents something that has confused Christians for centuries (1 Jn 3:6-9). They were not confused because of what John said, but because their teachers were confused. You can understand it if you compare Col 1:27 with 1 Jn 3:6-9 & 1:8-2:1. If we understand that the “new creation” is Christ being formed in us, a “new man” born of God and holy and blameless before Him, and that this “new creation” - the Spiritual Man - is still bound to “this body of death” - the natural man - we can understand what John is talking about. The Spiritual Man cannot sin; he is incapable by his nature of doing so. The natural man, by his nature, cannot do anything else except sin. John is pointing out the truth that we need to live (walk) in such a way that the Spiritual Man will have the ascendancy and the natural man will be yielded to his control (1 Jn 2:6; 3:4-9)“Man is by original nature, through the assistance of divine grace, free and able to perform the right; but is, in his fallen state, of and by himself, unable to do so; he needs to be regenerated in all his powers before he can do what is good and pleasing to God.”
Ernest S. Williams, 