Saturday vs. Sunday: How History Shifted the Sabbath Day of Rest

The move from Saturday to Sunday took centuries, and this study traces it through the original sources, from Creation and the apostles to Constantine, Laodicea, and the Reformation.

Your teenager comes home from a world history class and asks a simple question over dinner. If the Ten Commandments name the seventh day, why do most churches meet on the first? You start to answer, then realize you are not sure. Later that night you look up the history of the sabbath change from saturday to sunday, and the results argue with each other: one blames an emperor, another credits the apostles, and a third points to a pope.

That confusion is understandable, because each of those answers holds a piece of the story and none of them holds all of it. It unfolded across several centuries, in different cities, for different reasons, and the people involved left writings we can still read. Some of what circulates online about those writings is accurate, and some of it is garbled.

So this article does one thing. It walks through the record in order, from Creation to the Reformation, and lets the sources speak in their own words. Where a text is unclear, we will say so, and where Christians read the evidence differently, we will describe their views fairly. Like the people of Berea, who "searched the scriptures daily, whether those things were so" (Acts 17:11, KJV), you are invited to check everything here for yourself.

The short answer

The shift from Saturday to Sunday was gradual, and no single person made it. Christians were meeting on Sunday by the middle of the second century, as Justin Martyr records. Constantine's law of AD 321 then gave Sunday civil rest, and the Council of Laodicea later pressed believers to work on the Sabbath. Scripture records no such change, so the seventh day remains the Sabbath of the fourth commandment.

That last sentence is a conclusion drawn from reading the Bible, and many sincere Christians reach a different one. The historical facts themselves are shared ground, though. Few who have studied the sources think one emperor flipped a switch, and few claim the New Testament contains a direct command to move the day. What people disagree about is what the slow change means.

Where does the Sabbath story begin?

The Sabbath begins in the first pages of the Bible, not at Mount Sinai. Genesis says that after the sixth day of Creation God rested, and then it adds: "And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made" (Genesis 2:3, KJV). When the Ten Commandments were given, the fourth one pointed straight back to that moment. It says, "But the seventh day is the sabbath of the LORD thy God" (Exodus 20:10, KJV), and it gives Creation as the reason.

For the history that follows, one detail matters a great deal. The commandment does not only ask for a weekly rest. It names a particular day and ties it to something God did. That is why the later change is such an interesting question, and why people on every side of it have felt the need to explain it.

Did Jesus and the apostles change the Sabbath?

The New Testament does not record Jesus or the apostles changing the Sabbath to another day. Luke says Jesus went to the synagogue at Nazareth on the Sabbath "as his custom was" (Luke 4:16, KJV). Jesus disputed how the day was kept, but He defended it rather than removing it, saying, "The sabbath was made for man, and not man for the sabbath" (Mark 2:27, KJV). After the crucifixion, Luke notes that the women who followed Him "rested the sabbath day according to the commandment" (Luke 23:56, KJV), and Luke wrote those words years after the resurrection.

The book of Acts shows the same day in use across the Roman world. Paul entered the synagogue at Thessalonica "as his manner was" and "three sabbath days reasoned with them out of the scriptures" (Acts 17:2, KJV). At Antioch in Pisidia, Gentiles asked to hear more, and "the next sabbath day came almost the whole city together to hear the word of God" (Acts 13:44, KJV). Many Christians reply, reasonably, that Paul went to synagogues on the Sabbath because that was where he could find an audience. That is a fair point, and these verses alone do not settle the question.

What about the first day of the week in the New Testament?

The New Testament mentions the first day of the week a handful of times, but no passage says the Sabbath moved to it. Paul met with believers at Troas "upon the first day of the week, when the disciples came together to break bread" (Acts 20:7, KJV), and he told the Corinthians to set money aside on "the first day of the week" (1 Corinthians 16:2, KJV). John also wrote, "I was in the Spirit on the Lord's day" (Revelation 1:10, KJV), without saying which day he meant. Many Christians see in these verses the seeds of Sunday worship, and this article reads them differently.

Those passages deserve careful study of their own, which is why we treat them in a separate article rather than here. For the purposes of history, one observation is worth holding on to. Acts records a sharp public dispute over whether Gentile believers must be circumcised, yet it records no dispute at all about a change of the weekly day. That is an argument from silence, so it should be held with some modesty, but it does suggest that no such change was being pressed in those years.

What do we know about the Sabbath in the early church?

The evidence from the first decades after the apostles is thin, and honesty requires saying so. A Roman governor, Pliny the Younger, reported around AD 112 that Christians met "on a fixed day before dawn" (Letters 10.96), but he does not say which day. An early church manual called the Didache, whose date is debated though many scholars place it in the first century, tells believers, "But every Lord's day gather yourselves together, and break bread." Even there the Greek is unusual, and the word "day" has been supplied by the translator, so scholars discuss what the phrase originally meant.

What did Ignatius and Barnabas say?

Ignatius of Antioch and the letter of Barnabas are two of the earliest writers usually cited, and neither is as simple as the slogans suggest. In the standard English translation, Ignatius describes believers as "no longer observing the Sabbath, but living in the observance of the Lord's Day" (Magnesians 9). The trouble is that the word "Day" is not in the main surviving Greek manuscript, which reads more like living according to the Lord's life. Fritz Guy examined the passage in Andrews University Seminary Studies in 1964 and concluded that it is too ambiguous to serve as clear evidence, though other scholars do read it as a reference to Sunday.

The letter of Barnabas, written by an unknown author, is plainer. It treats the present Sabbath as something God does not accept and then says, "we keep the eighth day with joyfulness," calling it "the day also on which Jesus rose again from the dead" (Barnabas 15). This is a real witness to a Christian Sunday observance, and it would be unfair to explain it away. It is also worth noticing that the writer does not say the Sabbath moved to the eighth day. He presents the eighth day as something new, with its own meaning.

What did Justin Martyr really write?

Justin Martyr, a Christian teacher at Rome, gives the first detailed description of a Christian Sunday service, written around the middle of the second century. In his First Apology, chapter 67, he says, "But Sunday is the day on which we all hold our common assembly," and he describes Scripture reading, teaching, prayer, the bread and wine, and gifts for widows and orphans. He gives two reasons: God began Creation on that day, and Jesus rose on it. This was roughly 170 years before Constantine's law, so anyone who claims that Constantine invented Sunday worship is simply mistaken.

Justin also helps us understand how he thought about the Sabbath, and he is often misread here. He did not teach that the Sabbath had moved to Sunday. In his Dialogue with Trypho he argues that the Sabbath was a sign given to Israel, and that it was no longer needed now that Christ had come. He says, "The new law requires you to keep perpetual sabbath" (chapter 12), meaning a whole life of faithfulness. Yet in chapter 47 he says that a believer in Christ who still keeps the law of Moses "will be saved" if he does not press it on others, and he admits that some Christians refused fellowship with such people. In other words, Sabbath keeping believers were still around in his day, and the church had not reached one mind about them.

Why did Sunday gain ground?

Scholars give several reasons for the growth of Sunday, and they do not all agree on how the reasons fit together. The reason the early writers themselves give is the resurrection, and that deserves real respect. Christianity Today's Christian History magazine says that no single name or date is attached to the change, that growing numbers of Gentile converts played a part, and that Sunday was the norm by the end of the first century. Samuele Bacchiocchi, a Sabbath keeping scholar writing in Biblical Archaeology Review in 1978, argued for a later date and a different place. He held that the change came "sometime after 135 A.D.," started in Rome rather than Jerusalem, and was spurred by Roman repressive measures after the Jewish revolts.

Both views are held by serious people, and the sources are thin enough that neither can claim the last word. Bacchiocchi's Rome theory has also been challenged, even by another Sabbath keeping scholar. Around AD 200, Tertullian in North Africa shows the practice maturing. He says that on the day of the resurrection Christians should avoid kneeling, "deferring even our businesses" (On Prayer 23), which is an early hint of setting work aside. In his Apology, chapter 16, he also has to answer pagans who assumed that Christians worshiped the sun, and he insists that their joy on that day has a different cause. His same discussion of kneeling notes that "some few" also avoided kneeling on the Sabbath, a small sign that the seventh day still held meaning for some.

What did Constantine's Sunday law of 321 actually say?

Constantine's law of March 7, 321 ordered city dwellers and workshops to stop work on the day of the Sun, while allowing farmers to continue. Philip Schaff, the church historian, translates its opening this way: "On the venerable Day of the Sun let the magistrates and people residing in cities rest, and let all workshops be closed." The law survives in the Code of Justinian, book 3, title 12, where its Latin phrase is "venerabili die Solis." Elsewhere in the same history, Schaff notes that many church histories leave out the exception for farm work, which was allowed because planting could not always wait.

The wording shows what the law was and what it was not. Schaff writes, "There is no reference whatever in his law either to the fourth commandment or to the resurrection of Christ." It uses the old name for the day, which he suggests could speak to pagan and Christian subjects at once, and he calls Constantine the founder, in part at least, of the civil observance of Sunday. Later that same year another decree allowed slaves to be freed on the day. So Constantine did not create Christian Sunday worship, and he did not abolish the Sabbath. What he did was give an existing Christian custom the weight of Roman law, and that mattered a great deal.

What did the Council of Laodicea decide?

The Council of Laodicea was a regional church gathering in the fourth century that told Christians not to rest on the Sabbath. Its exact date is uncertain, and the introduction in the New Advent edition places it somewhere between AD 343 and 381. Canon 29 reads, "Christians must not judaize by resting on the Sabbath, but must work on that day, rather honouring the Lord's Day; and, if they can, resting then as Christians." It closes by declaring that those found to be judaizers are to be "anathema from Christ," which is the language of being cut off.

Two details are often missed, and they make the picture more interesting. First, this canon came from one regional council, not from the whole church, and its Sunday instruction is gentle: rest "if they can." Second, the same council did not treat the Sabbath as an ordinary day. Canon 16 says, "The Gospels are to be read on the Sabbath," and canons 49 and 51 set the Sabbath beside the Lord's Day as the two days for certain observances in Lent. It seems reasonable to conclude that a rule against resting on the Sabbath would not be needed unless some Christians were still doing so, though the canon itself does not tell us how many.

How long did Christians keep both days?

Many Christians gathered on both days well into the fifth century, according to two historians of that period. Socrates Scholasticus wrote that "almost all churches throughout the world celebrate the sacred mysteries on the sabbath of every week," and he adds that Christians at Alexandria and Rome had stopped doing so "on account of some ancient tradition" (Church History 5.22). His contemporary Sozomen says that the people of Constantinople, "and almost everywhere, assemble together on the Sabbath, as well as on the first day of the week," a custom never observed at Rome or at Alexandria (Church History 7.19). Neither writer says these churches rested from work as the fourth commandment directs, so these reports describe gatherings, not full Sabbath keeping.

Their reports still correct a common picture. The move was not a clean swap in which one day ended and another began. For several hundred years the two days overlapped, with different customs in different regions.

Who changed the Sabbath to Sunday, according to the churches themselves?

Different Christian traditions answer this question differently, and it helps to let each one speak for itself. Thomas Aquinas, the great medieval Catholic teacher, wrote that "the observance of the Lord's day took the place of the observance of the Sabbath, not by virtue of the precept but by the institution of the Church and the custom of Christian people" (Summa Theologiae, Second Part of the Second Part, question 122, article 4). The Catechism of the Catholic Church, paragraph 2175, says of Sunday that "for Christians its ceremonial observance replaces that of the sabbath," and it adds, "In Christ's Passover, Sunday fulfills the spiritual truth of the Jewish sabbath." The same paragraph also says that Sunday "is expressly distinguished from the sabbath which it follows chronologically every week," so on the Catechism's own terms the two days remain distinct.

Protestants have not spoken with one voice either. The Augsburg Confession of 1530, a founding Lutheran statement, reports in its public domain English translation that its opponents point to the change as proof of church authority, saying, "Great, say they, is the power of the Church, since it has dispensed with one of the Ten Commandments!" It rejects that argument, teaching instead that the Sabbath has been set aside by Scripture and that "the Church designated the Lord's Day" so people would know when to assemble. The Westminster Confession of the 1640s takes another path, saying that the Sabbath was the last day of the week until the resurrection of Christ, and then "was changed into the first day of the week." So one tradition points to the Church, one to Christian liberty, and one to a change made at the resurrection.

Reading these statements side by side is striking, and it calls for humility rather than point scoring. These are thoughtful Christians trying to be faithful, and they agree on the most important fact about Jesus: He rose from the dead. Yet their different explanations show that the change is not something the Bible states in a single clear sentence. Our reading is that God blessed the seventh day, that Scripture never transfers that blessing, and that the Sabbath still stands, while the resurrection remains the center of our hope on every day of the week.

How can you weigh this history for yourself?

The best way to weigh this history is to go back to the documents and to read them slowly. Every passage quoted here is short enough to read in one sitting, and most are free online. Start with the Bible, then read Justin, Constantine's law, and Laodicea in that order, and notice who is speaking and when. A family could do this over a few evenings.

Be careful with quotations, too, since this is one topic where a striking line can travel a long way without its source. Some statements credited to popes, cardinals, and reformers are hard to trace, and others have been trimmed until they say more than the author meant. We left out any statement we could not read in its original setting. That habit protects truth, and it also protects the people we quote, who deserve to be represented as they actually wrote.

Questions people ask

Did Constantine change the Sabbath to Sunday?

No, Constantine did not change the Sabbath to Sunday on his own, because Christians were already meeting on Sunday long before his law of AD 321. Justin Martyr describes such a gathering around the middle of the second century. What Constantine did was order civil rest on the day of the Sun in the cities, which gave Sunday standing in Roman law. His law strengthened the custom, but it says nothing about the Sabbath or the fourth commandment.

Is Saturday the Sabbath?

Yes, Saturday is the seventh day of the week, the day the Bible calls the Sabbath. Luke's account places the Sabbath between the day Jesus died and the first day of the week, and Justin Martyr says that Jesus was "crucified on the day before that of Saturn" and rose the day after it. That places the Sabbath on Saturn's day, the day we call Saturday. Many who worship on Sunday agree on this point, even though they explain the change of worship differently.

Did the Catholic Church change the Sabbath?

The answer depends on what is meant, because Sunday worship began before there was any decision by a pope or a universal council. Aquinas does credit the institution of the Church and Christian custom for the Lord's Day taking the Sabbath's place, and the Catechism teaches that Sunday's observance replaces that of the Sabbath. Catholics today would add that the practice goes back to the earliest Christians and honors the resurrection. Historically, the fairest summary is that the change grew over centuries through Christian custom, church rulings, and civil law, rather than one act.

Is Saturday vs Sunday worship a question of salvation?

No, keeping a day does not save anyone, because salvation comes by grace through faith in Jesus Christ. The question is about a faithful response to what God has said, not about earning His love, because obedience to His commandments is the fruit of salvation and never its cause. Justin Martyr's own century shows Christians struggling with this, and his willingness to call Sabbath keeping believers "kinsmen and brethren" is a good reminder to treat one another gently. Millions of Sunday keeping Christians love Jesus sincerely, and God knows every one of them.

Reflection questions

Take a few quiet minutes with these questions, alone or with your family. When you learned where your own weekly worship habits came from, did the history surprise you, and why? How do you decide between a long custom and the plain words of Scripture when the two seem to point in different directions? And how could you talk about this subject with a Christian friend in a way that leaves them feeling more loved, not less?

A word of encouragement

History can feel like a heavy subject, but it does not have to weigh you down. If you have kept Sunday all your life, there is no shame in learning something new, and no one is asking you to doubt the faith you have known in Jesus. God has been patient with His people through every century of this story, and He is patient with you. The same Savior who is Lord of the Sabbath still says, "Come unto me, all ye that labour and are heavy laden, and I will give you rest" (Matthew 11:28, KJV). You can bring your questions to Him without fear.

A prayer

Father in heaven, thank You for the gift of Your Word and for all who have loved You through the long centuries. Give us honest minds as we read history and humble hearts as we read Scripture. Help us to treat our brothers and sisters with kindness, even when we see things differently. Lead us by Your Spirit into all that You would have us know, and keep our eyes on Jesus, who died and rose for us. In His name we pray, Amen.

Your next step

If this history has left you wanting to look more closely at what the Bible says, the best next step is a free Bible study. Shekinah church in Alvarado, Texas offers free Bible studies for anyone who wants to read the Scriptures with a patient guide, whether you keep Saturday, keep Sunday, or are not sure what you believe yet. Bring your questions, including the hard ones from this article. Request a study below, and we will be glad to open the Bible with you.

"And God blessed the seventh day, and sanctified it: because that in it he had rested from all his work which God created and made." Genesis 2:3, KJV