{49} respecting the Faith of the Church. [Sidenote: Development of the teaching of the Church.] Held firmly in its fulness from the beginning, it was yet only gradually set forth in Creeds, Liturgies, and Definitions of Faith, according as the love and belief of Christians required expression, or the errors of heretics drew forth clearer teaching on the truths they attacked. [Sidenote: Reserve in the teaching of the Church.] To this we may add, that the early Church was very careful to keep the knowledge of the deep mysteries of the Faith from those who were not Christians. It was only after their initiation by Holy Baptism that those who had, as Catechumens, been instructed in the rudiments of Christian doctrine, were admitted to a full knowledge of the belief and practice of the Church, especially as regarded the Holy Eucharist, which was very commonly spoken of under the name of the Holy Mysteries. Section 3. _St. John at Ephesus[5]._ [Sidenote: St. John's work at Ephesus.] About the time that Jerusalem was besieged by the armies of Vespasian (A.D. 67), St. John withdrew to Ephesus (whence for a while he was banished to Patmos by the Emperor Domitian[6]); and from this city he travelled about through the neighbouring country, organizing, amongst others, those Seven Churches of Asia Minor, to whose Angels or Bishops he was bidden to write the Seven Epistles contained in the Apocalypse. {50} [Sidenote: Fitness of Ephesus as a centre of organization,] Here in Ephesus, the eye of Asia, the great mercantile seaport of the then known world, his influence could most easily make itself felt amongst the far-off members of the Christian body, which by this time had extended throughout the whole Roman empire. All the civilized world was then subject to the sway of Rome, except India and China; and it may be that even these two latter countries were not excluded from the influence of the Gospel. It is not, of course, meant that Christianity was the recognized religion of all or any of the Roman provinces; but that in each of them the Church had a corporate existence, and was a living power, drawing into herself here one, and there another of the souls who were brought into contact with her, and really, though gradually, spreading through and leavening the earth. [Sidenote: and of orthodox teaching.]