Question 190: When was the Shabbat changed from the seventh day (Saturday) to the first day of the week (Sunday)?

Answer:

The New Testament indicates that the Jewish believers held both days holy. Paul evidently preached in the synagogues on the Shabbat, but it was on the first day of the week that the Gentile believers met to break bread (Acts 20:7). This second sacred day was called Elohiym's Day to distinguish it from the Shabbat and was probably the only one observed by the Gentile converts. There is a hint of their being called to account for observing that day only, in Colossians 2 :16, where Paul bids them pay no heed to their critics. The Teaching of the Twelve Apostles, written certainly before the year 100 A.D., speaks of Elohiym's Day and refers to it as a day of holy meeting and the breaking of bread (chapter 14). The primitive believers everywhere kept it so solemnly. Pliny, the historian, refers to this fact in his letter to Trajan. Justin Martyr (A D. 140) describes the religious worship of the early believers, their sacramental observances, etc., on the "First Day." Other early writers who make clear and unmistakable reference to Elohiym's Day are Dionysius of Corinth, Irenaeus of Lyons (who asserted that the Shabbat was abolished), Clement of Alexandria, Tertullian, Origen, Cyprian, Commodian, Victorious, and lastly Peter of Alexandria (A.D. 300), who says: "We keep Elohiym's Day as a day of joy because of him who rose thereon." These evidences cover the first two centuries after our Saviour's death and indicate that Elohiym's Day is an institution of apostolic sanction and custom. All grounds of doubt are swept away by the fact that Constantine in an edict issued in A. D. 321 honoured that day by recognizing it as one sacred to the believers and ordered that business should be intermitted thereon. Finally, the Council of Nicea (A.D. 325) in its official proceedings gave directions concerning the forms of worship on that day and the Council of Laodicea (A.D. 364) enjoined rest on Elohiym's Day. Thus, by apostolic) usage, by law and custom, by imperial edict and by the highest councils of the early Church the change has been accepted and approved.