These sects arose precisely because within the Catholic Church (1) exact doctrine, (2) unbroken tradition, and (3) absolute unity, were, all three, regarded as the necessary marks of the institution. The heresies arose one after another, from the action of men who were prepared to define yet more punctiliously what the truth might be, and to claim with yet more particular insistence the possession of living tradition and the right to be regarded as the centre of unity. No heresy pretended that the truth was vague and indefinite. The whole gist and meaning of a heresy was that it, the heresy, or he, the heresiarch, was prepared to make doctrine yet more sharp, and to assert his own definition.
What you find in these foundational times is not the Catholic Church asserting and defining a thing and then, some time after, the heresiarch denying this definition; no heresy comes within a hundred miles of such a procedure. What happens in the early Church is that some doctrine not yet fully defined is laid down by such and such a man, that his final settlement clashes with the opinion of others, that after debate and counsel, and also authoritative statement on the part of the bishops, this man’s solution is rejected and an orthodox solution is defined. From that moment the heresiarch, if he will not fall into line with defined opinion, ceases to be in communion; and his rejection, no less than his own original insistence upon his doctrine, are in themselves proofs that both he and his judges postulate unity and definition as the two necessary marks of Catholic truth.
No early heretic or no early orthodox authority dreams of saying to his opponent: “You may be right! Let us agree to differ. Let us each form his part of ‘Christian society’ and look at things from his own point of view.” The moment a question is raised it must of its nature, the early Church being what it was, be defined one way or the other.
Well, then, what was this body of doctrine held by common tradition and present everywhere in the first years of the third century?
Let me briefly set down what we know, as a matter of historical and documentary evidence, the Church of this period to have held. What we know is a very different matter from what we can guess. We may amplify it from our conceptions of the probable according to our knowledge of that society—as, for instance, when we say that there was probably a bishop at Marseilles before the middle of the second century. Or we may amplify it by guesswork, and suppose, in the absence of evidence, some just possible but exceedingly improbable thing: as, that an important canonical Gospel has been lost. There is an infinite range for guesswork, both orthodox and heretical. But the plain and known facts which repose upon historical and documentary evidence, and which have no corresponding documentary evidence against them, are both few and certain.
Let us take such a writer as Tertullian and set down what was certainly true of his time.
Tertullian was a man of about forty in the year 200. The Church then taught as an unbroken tradition that a Man who had been put to death about 170 years before in Palestine—only 130 years before Tertullian’s birth—had risen again on the third day. This Man was a known and real person with whom numbers had conversed. In Tertullian’s childhood men still lived who had met eye witnesses of the thing asserted.
This Man (the Church said) was also the supreme Creator God. There you have an apparent contradiction in terms, at any rate a mystery, fruitful in opportunities for theory, and as a fact destined to lead to three centuries of more and more particular definition.
This Man, Who also was God Himself, had, through chosen companions called Apostles, founded a strict and disciplined society called the Church. The doctrines the Church taught professed to be His doctrines. They included the immortality of the human soul, its redemption, its alternative of salvation and damnation.
Initiation into the Church was by way of baptism with water in the name of The Trinity; Father, Son and Holy Ghost.