Just as the head and body of a man form one single man, so the Son of the Virgin and those he has chosen to be his members form a single man and the one Son of Man. Christ is whole and entire, head and body, say the Scriptures, since all the members form one body, which with its head is one Son of Man, and he with the Son of God is one Son of God, who himself with God is one God. Therefore the whole body with its head is Son of Man, Son of God, and God. This is the explanation of the Lord’s words: Father, I desire that as you and I are one, so they may be one with us. And so, according to this well-known reading of Scripture, neither the body without the head, nor the head without the body, nor the head and body without God make the whole Christ. When all are united with God they become one God. The Son of God is one with God by nature; the Son of Man is one with him in his person; we, his body, are one with him sacramentally. Consequently those who by faith are spiritual members of Christ can truly say that they are what he is: the Son of God and God himself. But what Christ is by his nature we are as his partners; what he is of himself in all fullness, we are as participants. Finally, what the Son of God is by generation, his members are by adoption, according to the text: As sons you have received the Spirit of adoption, enabling you to cry, Abba, Father.