65. The Order of Public Worship. (Chapter 5: Christian Worship.) (History of the Christian Church) (Schaff, Philip)

The earliest description of the Christian worship is given us by a heathen, the younger Pliny, a.d. 109, in his well-known letter to Trajan, which embodies the result of his judicial investigations in Biyournia. According to this, the Christians assembled on an appointed day (Sunday) at sunrise, sang responsively a song to Christ as to God, and then pledged themselves by an oath (sacramentum) not to do any evil work, to commit no theft, robbery, nor adultery, not to break their word, nor sacrifice property intrusted to them. Afterwards (at evening) they assembled again, to eat ordinary and innocent food (the agape).

This account of a Roman official then bears witness to the primitive observance of Sunday, the separation of the love-feast from the morning worship (with the communion), and the worship of Christ as God in song.

Justin Martyr, at the close of his larger Apology, describes the public worship more particularly, as it was conducted about the year 140. After giving a full account of baptism and the holy Supper, to which we shall refer again, he continues:

On Sunday a meeting of all, who live in the cities and villages, is held, and a section from the Memoirs of the Apostles (the Gospels) and the writings of the Prophets (the Old Testament) is read, as long as the time permits. When the reader has finished, the president, in a discourse, gives all exhortation to the imitation of these noble things. After this we all rise in common prayer. At the close of the prayer, as we have before described, bread and wine with water are brought. The president offers prayer and thanks for them, according to the power given him, and the congregation responds the Amen. Then the consecrated elements are distributed to each one, and partaken, and are carried by the deacons to the houses of the absent. The weathy and the willing then give contributions according to their free will, and this collection is deposited with the president, who therewith supplies orphans and widows, poor and needy, prisoners and strangers, and takes care of all who are in want. We assemble in common on Sunday because this is the first day, on which God created the world and the light, and because Jesus Christ our Saviour on the same day rose from the dead and appeared to his disciples.

Here, reading of the Scriptures, preaching (and that as an episcopal function), prayer, and communion, plainly appear as the regular parts of the Sunday worship; all descending, no doubt, from the apostolic age. Song is not expressly mentioned here, but elsewhere. The communion is not yet clearly separated from the other parts of worship. But this was done towards the end of the second century.

The same parts of worship are mentioned in different places by Tertullian.

The eighth book of the Apostolical Constitutions contains already an elaborate service with sundry liturgical prayers.