Chapter 11 — Part I — Article IX (Of the Church)
Section 261. Q. How does it agree with the unity of the Church, that there are many separate and independent churches, as those of Jerusalem, Antioch, Alexandria, Constantinople, Russia? A. These are particular churches, or parts of the one Catholic Church: the separateness of their visible organization does not hinder them from being all spiritually great members of the one body of the Universal Church, from having one Head, Christ, and one spirit of faith and grace. This unity is expressed outwardly by unity of Creed, and by communion in prayer and Sacraments.