The catechisms of those churches which possess the greatest number of communicants, the Catholic, the Orthodox, and the Lutheran, express this in the plainest language.
The Catholic catechism says: "Quels sont ceux qui sont hors de l'Eglise? Les infidèles, hérétiques, et schismatiques."[5] By schismatics it means the so-called Orthodox, and by heretics the Lutherans; so that, according to the Catholic catechism, the Church is composed only of Catholics.
In the so-called Orthodox catechism it says: "The name Church of Christ means only the Orthodox Church, which has remained in perfect union with the universal Church. As to the Roman Church and the Protestant creeds" (they are not even called a church), "they cannot belong to the one true Church, for they have separated themselves from it."
According to this definition the Catholics and the Protestants are outside of the Church, and only the Orthodox are in it.
The Lutheran catechism says: "Die wahre Kirche wird darein erkannt, das in ihr das Wort Gottes lauter und rein ohne Menschenzusetzung gelehrt und die Sacramenten treu nach Christ Einsetzung gewartet werden."[6]
According to this definition, those who have added anything whatsoever to the teaching of Christ and the apostles, as the Catholic and Greek Churches have done, are outside the Church, and the Lutherans alone are in it.
The Catholics assert that the Holy Ghost dwells perpetually with their hierarchy; the Orthodox assert that the same Holy Ghost resides also with them; the Arians claim that the Holy Ghost manifests itself to them (and they have the same right to assert this as have the prevailing religions of the present day); all the denominations of Protestants—Lutherans, Reformed Presbyterians, Methodists, Swedenborgians, and Mormons—assert that the Holy Ghost manifests itself only with them.
If the Catholics assert that the Holy Ghost during the separation of the Arian and Greek Churches withdrew from the separating churches and remained in the one true Church, then the Protestants of any denomination whatsoever may assert with as much right that during the separation of their Church from the Catholic, the Holy Ghost left the Catholic Church and entered into their own. And this is exactly what they do say. Every church professes to derive its creed by an unbroken tradition from Christ and the apostles. And certainly every Christian creed derived from Christ must have reached the present generation through tradition of some sort. But this is no proof that any one of these traditions embodies infallible truth, to the exclusion of all others.
Every branch proceeds from the root without interruption; but the fact that each one comes from one root, by no means proves it to be the only branch. And so it is in regard to the churches. The proofs which each church offers of its apostolic succession, and the miracles which are to prove its authenticity, are the same in every case; consequently there is but one exact definition of what is called a church (not the imaginary church which we may desire, but the actual church which has really existed). The Church is a body of men which lays claim to the exclusive possession of the truth. All these various societies which were afterward transformed by State authority into powerful organizations have really been the chief obstacles to the diffusion of true Christianity. It could not be otherwise: for the principal characteristic which distinguishes the doctrine of Christ from those of earlier times is that the men who accepted it strove to understand and to fulfil it more and more perfectly; whereas the doctrine of the Church affirmed that it was already thoroughly understood and also fulfilled.
However strange this may seem to us, reared as we have been in the false doctrine of the Church, as if it were a Christian institution, and taught to despise heresy, it is nevertheless in that which men call heresy that true progress, that is, true Christianity, was manifested, and it only ceased to be such when these heresies were checked, and it was, so to speak, stamped with the immutable imprint of the Church.