Catholic Christianity discovered the formula which reconciled faith and knowledge. This formula satisfied humanity for centuries, and the blessed effects which it accomplished continued to operate even after it had itself already become a fetter. Catholic Christianity grew out of two converging series of developments. In the one were set up fixed outer standards for determining what is Christian, and these standards were proclaimed to be apostolic institutions. The baptismal confession was exalted to an apostolic rule of faith, that is, to an apostolic law of faith. A collection of apostolic writings was formed from those read in the Churches, and this compilation was placed on an equal footing with the Old Testament. The episcopal and monarchical constitution was declared to be apostolic, and the attribute of successor of the Apostles was conferred on the bishop. Finally, the religious ceremonial developed into a celebration of mysteries, which was in like manner traced back to the Apostles. The result of these institutions was a strictly exclusive Church in the form of a communion of doctrine, ceremonial, and law, a confederation which more and more gathered the various communities within its pale, and brought about the decline of all nonconforming sects. The confederation was primarily based on a common confession, which, however, was not only conceived as "law," but was also very soon supplemented by new standards. One of the most important problems to be investigated in the history of dogma, and one which unfortunately cannot be completely solved, is to show what necessities led to the setting up of a new canon of Scripture, what circumstances required the appearance of living authorities in the communities, and what relation was established between the apostolic rule of faith, the apostolic canon of Scripture, and the apostolic office. The development ended with the formation of a clerical class, at whose head stood the bishop, who united in himself all conceivable powers, as teacher, priest, and judge. He disposed of the powers of Christianity, guaranteed its purity, and therefore in every respect held the Christian laity in tutelage.