According to this definition the Catholics and Lutherans are outside the church, and in the church are only the Orthodox.
But the Lutheran catechism runs as follows: "Die wahre Kirche wird daran erkannt, dass in ihr das Wort Gottes lauter und rein ohne Menschenzusätze gelehrt und die Sacramente treu nach Christi Einsetzung gewahrt werden."
According to this definition, all those who have added anything to the teaching of Christ and the apostles, as the Catholic and Greek Churches have done, are outside the church. And in the church are only the Protestants.
The Catholics assert that the Holy Ghost has uninterruptedly operated in their hierarchy; the Orthodox assert that the same Holy Ghost has operated in their hierarchy; the Arians asserted that the Holy Ghost operated in their hierarchy (this they asserted with as much right as the now ruling churches assert it); the Protestants of every description, Lutherans, Reformers, Presbyterians, Methodists, Swedenborgians, Mormons, assert that the Holy Ghost operates only in their assemblies.
If the Catholics assert that the Holy Ghost during the division of the Arian and of the Greek Churches left the apostatizing churches and remained only in the one, true church, the Protestants of every denomination can with the same right assert that during the separation of their church from the Catholic the Holy Ghost left the Catholic Church and passed over to the one which they recognize. And so they do.
Every church deduces its profession through an uninterrupted tradition from Christ and the apostles. And, indeed, every Christian confession, arising from Christ, must have inevitably reached the present generation through a certain tradition. But this does not prove that any one of these traditions, excluding all the others, is indubitably the correct one.
Every twig on the tree goes uninterruptedly back to the root; but the fact that every twig comes from the same root does in no way prove that there is but one twig. The same is true of the churches. Every church offers precisely the same proofs of its succession and even of the miracles in favour of its own authenticity; thus there is but one strict and precise definition of what the church is (not as something fantastic, which we should like it to be, but as something which in reality exists), and this is: the church is an assembly of men, who assert that they, and they only, are in the full possession of the truth.
It was these assemblies, which later on, with the aid of the support of the temporal power, passed into mighty institutions, that were the chief impediments in the dissemination of the true comprehension of Christ's teaching.
Nor could it be otherwise: the chief peculiarity of Christ's teaching, as distinguished from all the former teachings, consisted in this, that the men who accepted it tried more and more to understand and fulfil the teaching, whereas the church doctrine asserted the full and final comprehension and fulfilment of this teaching.
However strange it may seem to us people educated in the false doctrine about the church as a Christian institution, and in the contempt for heresy, it was only in what is called heresy that there was true motion, that is, true Christianity, and it ceased to be such when it stopped its motion in these heresies and became itself arrested in the immovable forms of the church.