So in this way it shows that we do not have the fullness of Christ. We start pretty much at empty and we need to be filled with the fullness of Christ until we get to the point where we are of His measure and stature.
So we start out where we need to get rid of a lot of our humanity and begin backfilling with the new man. And those things that we are putting on reflect true righteousness and holiness.
Now Paul described the futility of the Gentiles' way in previous verses and tells the Ephesians that this is not what they have been taught. They have been taught the truth that is in Jesus. Knowing the truth should produce a change that puts off the former conduct of sin, corruption, and the old way of life, and puts on the new person that God creates in us with His Holy Spirit after baptism.