Quote taken from The Cradle, The Cross, and the Crown: An Introduction to the New Testament by Andreas Köstenberger, L. Scott Kellum, and Charles Quarles.
The Lordship of Christ
“The ‘bringing back of all things…together again under one head’, the Lord Jesus Christ, is the central theme of the whole letter. God progressively brings about this realignment of proper authority and submission in two spheres: the heavens (1:3, 10, 20; 2:6; 3:10; 6:12); and the earth (1:10; 3:15; 4:9; 6:3). Each realm has its own representative: the powers in the heavens and the church upon the earth. Therefore, God’s subjection of all things to Christ becomes a progressive reality through Christ’s supremacy over and defeat of the evil powers (1:19-22) and his gathering together of both Jews and Gentiles into one body (2:11-22).”