The NT evidence does not compel the belief that the Lord's Day was of universal observance in the earliest ages of the Church, but it at least makes it probable (especially when we find it so generally established in the next age) that it was of Apos- tolic precept. And there is nothing to forbid the supposition that it was a following of the spirit of the teaching of the great Forty Days (Ac 1^). But we may gather, with the historian Socrates (HE V. 22), that the ' Sa\'iour and His Apostles ' did not make fixed rules as to the observance of days, and ' enjoined us by no law to keep this feast [he is speaking of Easter, but his argument ap])iies equally to Sunday], nor do the Gospels and Apostles threaten us with any penalty, ptinishment, or curse for the neglect of it, as the Mosaic Law does the Jews. . . . The aim of the Apostles was not to appoint festival days, but to teach a righteous life and piety.'
To pass to the post-Apostolic age, Barnabas (xv. 9) says : ' We keep the eighth day for rejoic- ing, in the which also Jesus rose from the dead, and, ha^'ing been manifested, ascended into the heavens,' a passage which throws some light on the occasional observance in later times of Ascen- sion Day and Pentecost together. Barnabas pur- posely names the ' eighth day ' rather than the first, as he has just spoken of it as following the Jewish Sabbath, the seventh day. 'I wUl make the beginning of the eighth day, which is the be- ginning of another world.' The Didachc speaks of the synaxis on the Lord's Day, and uses the pleon- astic phrase /cari KvpiaKi\v Ts.vplov (rwox^^t'-es ; the purpose of the synaxis was thaV the C li istians might break bread and celebrate tlie Eiu-.iarUt, having confessed their sins Miat their siu-ilice might be pure (§ 14). — Ignatius (Magn. § 9) spoiiks of Christians no longer observing Sabbaths, but fashioning their lives after the Lord's Day (m-vk^ti ca^PaTliovres, dWa koto KvpiaK^v fuvxes), which at least involves a general observance of the first day of the week. — Pliny {Ep. 96) says only that the Christians met on a fixed day, and does not say which ('soliti stato die ante hicem convenire car- menque Christo quasi deo dicere secum invicem . . . '). He apparently, as Lightfoot observes {Ifinntius-, i. p. 52), confuses Baptism and the Eucharist ; but we may probably gather from his account that the Christians of Bithj'nia met before
dawn on a fixed day to celebrate the Eucharist, and later in the day met for the Agape. This inference is disputed by some. — Justin Martyr describes the assembling ' on the day called Sun- day' {Ty Tou TjXiovXeyo^ifi n hu^i-a] f.irthe Eucharist by 'all who live in citii - .i in ih.' . (nmtry' (Apol. i. §67). He also expliriily in, m ions the Sunday collection of alms, as in I i u Hi . In the Dialogue also Justin extols the ' eighth day (cf . Barnabas, Lc.) as possessing a 'mysterious import,' which the .seventh day had not ; he is referring to the Jewish circumcision as a type of 'the true circumcision by which we are circumcised from deceit and ini- quity, through Him who rose from the dead on tlie first day after the Sabbath' (Dial. 24, 41).
That KvpiaK-q became a common name in the 2nd cent, for the first day of the week is further clear from the fact, which Eusebius tells us {HE iv. 26), that Melito, bishop of Sardis about A.D. 170, wrote a book vepi KvpiaKTJ^ (6 ir. k. XAyos). Dionysius of Corinth (A.D. 171) in his Epistle to Soter calls Sunday ' the Lord's Day ' (Eusebius, HE iv. 23 : tt}v Grip.cpov KvpiaKT]v aylav T)fiipav dnjya- yoti(v). After this the name becomes very com- mon, and we find it both in Greek (e.g. Clement of Alexandria, Strom, vii. 12) and in Latin, dies du- minica (e.g. TertuUian, de Cor. 3).
There is little evidence as to the way in which the Lord's Day was observed in the earliest ages. The Eucharist and probably the Agape were cele- brated ; but perhaps to a great extent other occu- pations went on much as usual. It would not be easy for Christian working men to absent them- selves from their avocations on a day when every- one around them was working ; and this may have been the reason why the synaxis took place at night or before dawn, as in the examples in Acts and in Pliny. St. Paul apparently began his journey from Troas (Ac 20) on Sunday. "There is no evidence in the earliest ages of any attempt to transfer the obligations of Sabbath observance to the Lord's Day. The Jewish Christians already had their day of rest on the Saturday. But, as Zahn observes (Skizzen aus dem Leben der Alien Kirehe, p. 214), the Gentile Christians must have very quickly learnt all over the world to keep the Lord's Day ; they were never compelled to Keep the Sabbath, which was not one of the four ob- servances enjoined in Ac 15'^.
TertuUian, however, is the first to mention a Sunday rest (Apologct. 16, de Orat. 23), saying that the Christians postponed ordinary duties and business only on that day, the day of the Lord's resurrection, and that they gave up ' the day of the sun' to joy. He contrasts the Christian with the Jewish rest by implication. He says that the Christians did not kneel on the Lord's Day (de Orat. 23, de Cor. 3). This custom we already find in Irena?us (Fragm. 7), who traces it to Apostolic times ; and it was afterwards laid down in the 20th canon of Niotea.