The New Testament was not created as a weapon in the conflict against heresy; there were many things in it that rendered it a very inconvenient weapon in this conflict, and that forced Tertullian to give the rather questionable and, indeed, useless warning not to engage in exegetical controversies with heretics, seeing that victory in such conflicts was uncertain or even improbable. Yet, however that might be, the New Testament, when once it was in existence, did form an excellent means of defence and offence against heresy. In the first place one might now simply adopt the standpoint: he who does not accept Scripture is eo ipso no Christian -- there was thus no need of further discussion. Or just as one denied to the Jews their property in the Old Testament, so now, by declaring that the New Testament belonged to the Church by Divine grant, one might chase heretics away from this Book and proclaim it to be abominable insolence, theft, and robbery that they should even venture a claim to the books contained in the New Testament. Such is already Tertullian's procedure (De Pr√¶sc., 37); |Non Christiani nullum ius capiunt Christianarum litterarum, ad quos merito dicendum est: qui estis? quando et unde venitis? quid in meo agitis, non mei? quo denique, Marcion, iure silvam meam c√¶dis? qua licentia, Valentine, fontes meos transvertis? qua potestate, Apelles, limites meos commoves? mea est possessio, quid hie, ceteri, ad voluntatem vestram seminatis et pascitis? mea est possessio, olim (?) possideo, prior possideo . . . ego sum h√¶res apostolorum!| The Church regarded the New Testament as her own peculiar possession divinely granted; she named herself the Church of the New Covenant with the same title as the book; in conflict, if it seemed fitting, she retired simply into this fortress; and firmly established herself, and gradually her adversaries also, in the conviction that Church and New Testament formed an exclusive unity, so that none but the Church had a right to the works contained in the Canon.
But in the New Testament the Church had created a possession that from her point of view was of very questionable advantage. Her Rule of Faith could be stretched, and was capable of development. The Church managed with it not so badly; when necessary, she treated it as invariable; where need became imperative, she modified and developed it, and could always draw a veil over these developments, such as they were. But it stood otherwise with the New Testament; littera manet! Even here, it is true, much that was desirable could be accomplished by manipulation, namely, by |interpretation|; but the letter full often set impassable bounds to such operations. The existence of a written fundamental document that could be held up as a mirror before the Church must have become as time went on more and more inconvenient and dangerous. And it was so employed -- by no means only by heretics, but, at first rarely and reluctantly, then more and more frequently, by faithful members of the Church. A beginning was already made by Origen, who earnestly and conscientiously measures the Church by the standard of the New Testament; and numbers of preachers in the Ancient Church followed his example. They themselves had no thought of leaving the Church because on the ground of the New Testament they had found so much fault with her; but even in their times the official Church had begun to consider whether she could tolerate members that with a certain recklessness held up the mirror before her, and she ended by deciding that she could not. Her judgment to-day is still the same. Yet since the time of the Waldensians and the Franciscans, what assaults have been made upon the Church from the base of the New Testament! What foes have drawn their weapons from this armoury and have forced the Church to fight hard for life! It is because the Church carried the New Testament with herself and before herself that reformations, that the Reformation, became possible; and the Reformed Church at least, because she must recognise this New Testament, must accept all that is drawn from this Book for her correction. Thus this collection of sacred writings has proved a great arsenal and a court of appeal for critics of the Church! When it was created, who could have suspected that this would be? The old proverb, |Habent sua fata libelli,| has here received most remarkable confirmation.