The new man is of Christ. It is His Body, created in Him on the cross (Eph. 2:15-16). It is not individual but corporate (Col. 3:10-11). In this corporate new man Christ is all and in all — He is all the people and in all the people. See note Col. 3:119d.
This book reveals first that the church is the Body of Christ (Eph. 1:22-23), the kingdom of God, the household of God (Eph. 2:19), and the temple, the dwelling place of God (Eph. 2:21-22). Here it reveals in addition that the church is the new man. This is the highest aspect of the church. The church is an assembly of the called-out ones. This is the initial aspect of the church. From here, the apostle went on to mention the fellow citizens of the kingdom of God and the members of the household of God. These are higher than the initial aspect, but not as high as the church as the Body of Christ. Yet the new man is higher still than the Body of Christ. Thus, the church is not just an assembly of believers, a kingdom of heavenly citizens, a household of God's children, or even a Body for Christ. It is in its ultimate, uttermost aspect a new man to accomplish God's eternal purpose. As the Body of Christ, the church needs Christ as its life, whereas as the new man, the church needs Christ as its person. This new corporate person should live a life like that which Jesus lived on earth, that is, a life of reality that expresses God and causes God to be realized as the reality by man. Hence, the new man is the focus of the apostle's exhortation in this section (vv. 17-32).