The Baptism of Constantine By Raphael
The Baptism of Constantine by Raphael

Did Constantine change the Sabbath to Sunday? When I was first challenged with this assertion I thought it must be a joke. Apparently, some people actually believe it. The fact of the matter is that Christians were commemorating the Resurrection on Sunday for nearly three centuries before Constantine made his proclamation calling for Sunday as an official day of rest. Here are a few quotes to support the Christian celebration of Sunday before Constantine:

In the Epistle of St. Ignatius of Antioch (~35-108 AD) to the Magnesians, we read:

If, therefore, those who were brought up in the ancient order of things have come to the possession of a new hope, no longer observing the Sabbath, but living in the observance of the Lord's Day, on which also our life has sprung up again by Him and by His death— whom some deny, by which mystery we have obtained faith, and therefore endure, that we may be found the disciples of Jesus Christ, our only Master— how shall we be able to live apart from Him, whose disciples the prophets themselves in the Spirit did wait for Him as their Teacher? And therefore He whom they rightly waited for, having come, raised them from the dead.

In the Epistle of Barnabas (~70-130 AD), we read:

You perceive how He speaks: Your present Sabbaths are not acceptable to Me, but that is which I have made, [namely this,] when, giving rest to all things, I shall make a beginning of the eighth day, that is, a beginning of another world. Wherefore, also, we keep the eighth day with joyfulness, the day also on which Jesus rose again from the dead.

St. Justin Martyr, in his First Apology, (155-157 AD) writes:

And on the day called Sunday, all who live in cities or in the country gather together to one place, and the memoirs of the apostles or the writings of the prophets are read, as long as time permits; then, when the reader has ceased, the president verbally instructs, and exhorts to the imitation of these good things. Then we all rise together and pray, and, as we before said, when our prayer is ended, bread and wine and water are brought, and the president in like manner offers prayers and thanksgivings, according to his ability, and the people assent, saying Amen; and there is a distribution to each, and a participation of that over which thanks have been given, and to those who are absent a portion is sent by the deacons.

In the Didache (~100AD) is written how Christians gathered on the “Lord’s Day”:

"And on the Lord's own day gather yourselves together and break bread and give thanks, first confessing your transgressions, that your sacrifice may be pure. And let no man, having his dispute with his fellow, join your assembly until they have been reconciled, that your sacrifice may not be defiled; for this sacrifice it is that was spoken of by the Lord; In every place and at every time offer me a pure sacrifice; for I am a great king, saith the Lord, and My name is wonderful among the nations."-14:1-3

Tertullian (~160-225 AD) in his “Ad Nationes” (Book 1) writes:

Others, with greater regard to good manners, it must be confessed, suppose that the sun is the god of the Christians, because it is a well-known fact that we pray towards the east, or because we make Sunday a day of festivity.

As you can see, the practice of observing the Sabbath had been abandoned or at least supplemented with Sunday worship by the early Christians prior to the edict of Constantine. The reason for this is that Sunday is the “Lord’s Day”. It is the day in which He rose from the dead. The early Christians no longer celebrated the Sabbath of the Old Testament. They celebrated the “Lord’s Day” since Jesus fulfilled the Old Testament and brought about the “second creation” by His salvific sacrifice on the Cross.