"The form and arrangement of Churches in primitive times was derived, in its main features, from the Temple at Jerusalem. Beyond the porch was the narthex, answering to the court of the Gentiles, and appropriated to the unbaptized and to penitents. Beyond the narthex was the nave, answering to the court of the Jews, and appropriated to the body of worshippers. At the upper end of the nave was the choir, answering to the Holy Place, for all who were ministerially engaged in Divine Service. Beyond the choir was the Berna or Chancel, answering to the Holy of Holies, used only for the celebration of the Holy Eucharist, and separated from the choir by a closed screen, resembling the organ screen of our cathedrals, which was called the Iconostasis. As early as the time of Gregory Nazianzen, in the fourth century, this screen is compared to the division between the present and the eternal world, and the sanctuary behind it was ever regarded with the greatest possible reverence as the most sacred place to which man could have access while in the body; the veiled door, which formed the only direct exit from it into the choir and nave, being only opened at the time when the Blessed Sacrament was administered to the people there assembled[3]. The opening of this door, then, brought into view the Altar and the Divine Mysteries which were being celebrated there. Its resemblance to what the Apocalypse tells us of Heaven. And when St. John looked through the door that had been opened in Heaven, what he saw is thus described: 'And behold a Throne was set in Heaven … and round about the Throne were four and twenty seats; and upon the seats I saw four and twenty elders sitting, clothed in white raiment; and they had on their heads crowns of gold … and there were seven lamps of fire burning before the Throne … and before the Throne there was a sea of glass like unto crystal.' Here is exactly represented an arrangement of the altar familiar to the whole Eastern Church and to the early Church of England, in which it occupies the centre of an apse in front of the seats of the Bishop and Clergy, which are placed in the curved part of the wall. And, although there is no reason to think that the font ever stood near the altar, yet nothing appears more likely than that the 'sea of glass like unto crystal' mystically represents that laver of regeneration through which alone the altar can be spiritually approached. Another striking characteristic of the ancient Church was the extreme reverence which was shown to the Book of the Gospels, which was always placed upon the altar and surmounted by a cross. So 'in the midst of the Throne, and round about the Throne,' St. John saw those four living creatures which have been universally interpreted to represent the four Evangelists or the four Gospels, their position seeming to signify that the Gospel is ever attendant upon the altar, penetrating, pervading, and embracing the highest mystery of Divine Worship, giving 'glory and honour and thanks to Him that sat on the Throne, who liveth for ever and ever.' In the succeeding chapter St. John beholds Him for whom this altar is prepared. 'I beheld, and lo, in the midst of the Throne, and of the four living creatures, and in the midst of the elders, stood a Lamb as It had been slain, having seven horns and seven eyes, which are the seven spirits of God sent forth into all the earth.' It cannot be doubted that this is our Blessed Lord in that Human Nature on which the septiformis gratia was poured without measure; and that His appearance in the form of 'the Lamb that was slain to receive power, and riches, and wisdom, and strength, and honour, and glory, and blessing,' represents the mystery of His prevailing Sacrifice and continual Intercession. But around this living Sacrifice there is gathered all the homage of an elaborate ritual. They who worship Him have 'every one of them harps' to offer Him the praise of instrumental music; they have 'golden vials full of incense, which are the prayers of saints,' even as the angel afterwards had 'given unto him much incense, that he should offer it with the prayers of the saints upon the golden altar which was before the Throne;' they sing a new song, mingling the praises of 'the best member that they have' with that of their instrumental music; and they fall down before the Lamb with the lowliest gesture of their bodies in humble adoration. Let it also be remembered that one of the Anthems here sung by the Choirs of Heaven is that sacred song, 'Holy, Holy, Holy, Lord God Almighty, which was, and is, and is to come;' the Eucharistic use of which is traceable in every age of the Church[9]."
The ritual of the early Church naturally gathered round the Holy Eucharist as the central act of worship in which the Lord was most especially present, and therefore to be most especially honoured. From the first days of the Church this had been the one distinctively Christian service; and now that the Temple services had ceased, it became more apparently even than before, the fulfilment and continuation of the sacrifices of the elder dispensations[10]: whilst it was also the Memorial of the Sacrifice of the Cross and the Representation on earth of the continual offering-up of "the Lamb as It had been slain," before the Throne of God in Heaven.
[1] St. Peter and St. John had been specially trained by their Divine Master for their special work. They with St. James, the first Apostolic martyr, had witnessed His Transfiguration, His Agony, His raising of Jairus's daughter, and had been admitted into more intimate communion with Him than the other Apostles.
[2] From passages in the works of St. Irenaeus and Eusebius. See "Some Account of the Church in the Apostolic Age," by Professor Shirley, pp. 136-140.
[3] The Apostles appear to have believed at first that our Lord's Ascension would be very speedily followed by His triumphal return to Judgment, and the glorification of His faithful people.
[4] On this point we may remember that St. John, who saw deepest into the Divine Life, did not write his Gospel till near the end of his earthly labours, almost sixty years after the Day of Pentecost.
[5] Ephesus is known to this day by the name of Aya-soluk, from Agios Theologos, or holy Divine, the title given to St. John.
[6] Or perhaps by Nero, as some ancient writers say. Nero's full name was Nero Claudius Domitianus, which may have caused this confusion.
[7] 1 Tim. vi. 20.
[8] As St. Chrysostom says, "When thou beholdest the curtains drawn up, then imagine that the heavens are let down from above, and that the Angels are descending."