This head has been given to the Church as to a body, so that the Church may be immortal. And so Christ, having risen, was the firstborn of those raised to eternal life. He appeared in the world above before God as the sacrificial firstfruits of a new planting of life in Christ. He will complete the salvation of all who believe in Him, and thereby manifest the fullness of His majesty.
According to Saint John Chrysostom, "When the Apostle says that Christ is the head of the Church, he wishes to show the Lord's nearness to us. He also shows the greatness of God's love for mankind, that He who is so exalted and above all was pleased to unite Himself so closely to our lowliness."
"He presents Him as the firstfruits, expressing the thought that the others are such as He is." "He is first everywhere: first in the things above, first in the Church as its head, and first in the resurrection."
"By every fullness the Apostle meant the fullness of the Godhead. As He is the Son and Word, as God, so He also dwelt in Him. It was not His operation that dwelt there, but He Himself, in His essence or in His full hypostasis."
To this His Grace Theophan adds: "In Him, Christ, the whole will of God was fulfilled. All God's plans and intentions, every divine good pleasure, come to accomplishment in Him."
This teaching on the fullness of the Godhead in Christ clearly has nothing in common with the heretical teaching expressed in the idea of a series of godlike beings, or aeons. These limit not only Christ but even God Himself, whom the highest of them supposedly reach by their height.
Scholars say instead: "The fullness of the Godhead, even according to Old Testament conceptions, stands in unconditional harmony with the unity of the personal God. The unity of the Godhead does not recede into the shadow before the multitude and variety of the manifestations of the Godhead."