CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 792–796

792 Christ "is the head of the body, the Church." He is the principle of creation and redemption. Raised to the Father's glory, "in everything he [is] preeminent," especially in the Church, through whom he extends his reign over all things.
793 Christ unites us with his Passover: all his members must strive to resemble him, "until Christ be formed" in them. "For this reason we . . . are taken up into the mysteries of his life, . . . associated with his sufferings as the body with its head, suffering with him, that with him we may be glorified."
794 Christ provides for our growth: to make us grow toward him, our head, he provides in his Body, the Church, the gifts and assistance by which we help one another along the way of salvation.
795 Christ and his Church thus together make up the "whole Christ" (Christus totus). The Church is one with Christ. The saints are acutely aware of this unity:

Let us rejoice then and give thanks that we have become not only Christians, but Christ himself. Do you understand and grasp, brethren, God's grace toward us? Marvel and rejoice: we have become Christ. For if he is the head, we are the members; he and we together are the whole man. . . . The fullness of Christ then is the head and the members. But what does "head and members" mean? Christ and the Church.

Our redeemer has shown himself to be one person with the holy Church whom he has taken to himself.

Head and members form as it were one and the same mystical person.

A reply of St. Joan of Arc to her judges sums up the faith of the holy doctors and the good sense of the believer: "About Jesus Christ and the Church, I simply know they're just one thing, and we shouldn't complicate the matter."

796 The unity of Christ and the Church, head and members of one Body, also implies the distinction of the two within a personal relationship. This aspect is often expressed by the image of bridegroom and bride. The theme of Christ as Bridegroom of the Church was prepared for by the prophets and announced by John the Baptist. The Lord referred to himself as the "bridegroom." The Apostle speaks of the whole Church and of each of the faithful, members of his Body, as a bride "betrothed" to Christ the Lord so as to become but one spirit with him. The Church is the spotless bride of the spotless Lamb. "Christ loved the Church and gave himself up for her, that he might sanctify her." He has joined her with himself in an everlasting covenant and never stops caring for her as for his own body:

This is the whole Christ, head and body, one formed from many . . . whether the head or members speak, it is Christ who speaks. He speaks in his role as the head (ex persona capitis) and in his role as body (ex persona corporis). What does this mean? "The two will become one flesh. This is a great mystery, and I am applying it to Christ and the Church." And the Lord himself says in the Gospel: "So they are no longer two, but one flesh." They are, in fact, two different persons, yet they are one in the conjugal union, . . . as head, he calls himself the bridegroom, as body, he calls himself "bride."