"Paul well knew the unbridgeable gulfs that exist between human beings. How can slave and master find common ground? Or the uncouth Scythian from northern Greece relate to the sophisticated freeman of Athens? But Paul is convinced of the power of Christ, not to bring people together while remaining just what they were before, but to change them so that a genuine meeting of mind and heart is achieved. Obviously the Jew cannot remain the person he was if Christ becomes all to him; nor will the proud Greek debater any more mock at the finality of the resurrection. In short, this kind of Christian unity is the result of genuine spiritual revolutions in individuals lives, where the old nature with all its prejudices and hatreds is put off and the the new nature put on"
Dick Lucas, the message of Colossians & Philemon (Bible speaks today commentary)