Arthur Michael Ramsey on the new creation and the “fullness” of Christ (2 Cor. 5: 14-17):

They used to think of Christ as an isolated historical figure (“after the flesh”); now they think of Him as the inclusive head and center of a new humanity, wherein a new creation of God is at work. The implication of this passage is far-reaching. Christ is here defined not as the isolated figure of Galilee and Judea but as one whose people, dead and risen with Him, are His own humanity. The fact of Christ includes the fact of the Church. And this is not a novel speculation added to the original Gospel; it springs from that Gospel. They synoptic record is unintelligible except the disciples share in it, and by sharing in it through the baptism of the Spirit they and all believers know the death and resurrection as a present fact. Thus when St. Paul describes the Church as the “Body” of Christ, and the “fullness” of Christ, he is not indulging in mystical adventures of his own; he is describing facts inherent in the Messiah’s work from its commencement. “One died for all, therefore all died”; to know this is to know “the Church which is his body, the fullness of him that filleth all in all.”

The Gospel and the Catholic Church, 29-30.