"The faith _once for all delivered_ unto the saints" (τῇ ἅπαξ παραδοθείσῃ τοῖς ἅγίοις πίστει): both the adverb, "once for all," and the aorist participle, "delivered," are worthy of special notice. "The faith" does not mean any set formula of articles of belief, nor the internal reception of Christian doctrine, but the _substance_ of it; it is equivalent to what St. Paul and the Evangelists call "the Gospel," viz. that body of truth which brings salvation to the soul that receives it. This Faith, or this Gospel, has been once for all delivered to Christians. No other will be given, for there is no other. Whatever may be delivered by any one in future cannot be a gospel at all. The one true Gospel is complete and final, and admits of no successors and no supplements (Gal. i. 6-9).
"The faith which was once for all delivered unto the saints." Does this exclude all possibility of a "development of Christian doctrine"? That depends upon what one means by "development." The expression has been interpreted to mean "that the increase and expansion of the Christian creed and ritual, and the variations which have attended the process in the case of individual writers and Churches, are the necessary attendants on any philosophy or polity which takes possession of the intellect and heart, and has had any wide or extended dominion; that from the nature of the human mind, time is necessary for the full comprehension _and perfection_ of great ideas; and that the highest and most wonderful truths, though communicated to the world once for all by inspired teachers, could not be comprehended all at once by the recipients, but, as received and transmitted by minds not inspired and through media which were human, have required only the longer time and deeper thought for their full elucidation."[108] If the ambiguous expression "and perfection" be omitted, one may readily allow that development of Christian doctrine in this sense has taken place. To say that time is needed for the _full comprehension_ of the great truths which were communicated to the Church once for all by the Apostles is one thing; to say that time is needed for the _perfection_ of those truths may or may not be quite another. And the manner in which the subject is treated in the famous Essay from which the passage just quoted is taken shows that what is meant by the "perfecting" of the truths is a very different thing from the full comprehension of their original contents; it means making additions to the original contents in order to remedy supposed deficiencies. In this sense it may be confidently asserted, and as loyal Christians we are bound to assert, that there is no such thing as development of Christian doctrine. If there be such a thing, then we cannot stop short with those developments which can in some measure be called Christian. The author himself reminds us that "no one has power over the issues of his principles; we cannot manage our argument, and have as much of it as we please, and no more" (p. 29). If the faith once for all delivered to the saints was defective, and needed to be supplemented by subsequent additions, why may not Christianity itself be, as some have maintained, only a phase in the development of religion, which in process of time is to be superseded by something wholly unchristian? The transition is easily made from the position of the _Essay on the Development of Christian Doctrine_ to that of Channing, that "it makes me smile to hear immortality claimed for Catholicism or Protestantism, or for any past interpretations of Christianity: as if the human soul had exhausted itself in its infant efforts; as if the men of one or a few generations could bind the energy of human thought and affection for ever;"[109] and thence to the position of Strauss, who, in his latest and most dreary work, on _The Old and the New Faith_, asks the question, "Are we still Christians?" and answers it emphatically in the negative. The chief doctrines of Christianity are to him childish or repulsive beliefs, which thoughtful men have long since left behind. We may still in some sense be religious; but Christianity has done its work, and is rightly being dismissed from the stage.[110] This is the advanced thinking of which St. John writes in his Second Epistle: "Everyone that _goeth onward_ (πᾶς ὁ προάγων), and _abideth not in the doctrine of Christ_, hath not God" (ver. 9). There is an advance which involves desertion of first principles; and such an advance is not progress, but apostasy.