Sunday or Sabbath? Why Christians Worship on the Lord's Day

"Isn't the Sabbath Saturday? Did the Roman Church or Constantine change it to Sunday? Are Sunday Christians breaking the fourth commandment?" These questions are asked by Seventh-day Adventists, by many Hebrew Roots and some Messianic believers, and by ordinary Christians who have simply read Exodus 20.

The answer has four parts: what the Sabbath was, what the New Testament does with it, what Christians were doing on the first day of the week before Constantine, and what the Church has actually kept since. Our infographic on Sunday worship before Constantine gives a quick version, and our article on Seventh-day Adventism sets out that movement's beliefs; this article does not repeat either.

In brief

The Sabbath of Exodus 20 was given to Israel as a sign of the covenant and a memorial of creation and the Exodus. The New Testament treats it as "a shadow of things to come" fulfilled in Christ (Colossians 2:16-17), refuses to impose it on Gentile believers (Acts 15), and tells Christians not to judge one another over days (Romans 14:5). From the Resurrection onward the first day of the week is the day on which Christians gather. The evidence is the Gospels, Acts, 1 Corinthians and Revelation, and then the Didache, Ignatius, Barnabas, Pliny and Justin Martyr, all written well before Constantine's law of 321. That law was a civil rest day, not a change of worship. The Orthodox Church keeps Sunday as the weekly Pascha, the Lord's Day and "eighth day," while still honoring Saturday with its own services and memorials. Ellen White's claim that the change to Sunday is the sign of Rome's authority, "the mark of the beast," rests on the assumption that the Church changed God's law by her own authority; the evidence shows instead that the apostolic Church gathered on the Lord's Day from the start.

Thesis: Christians keep the Lord's Day because the apostolic Church did, from the Resurrection, and the weekly Sabbath of the old covenant was a shadow fulfilled in Christ, not a commandment binding on the new Israel.

What the Sabbath was

The fourth commandment is plain: "Remember the sabbath day, to keep it holy. Six days shalt thou labour, and do all thy work: But the seventh day [is] the sabbath of the LORD thy God" (Exodus 20:8-10). Exodus grounds it in creation (20:11). Deuteronomy gives a second ground: "remember that thou wast a servant in the land of Egypt ... therefore the LORD thy God commanded thee to keep the sabbath day" (Deuteronomy 5:15). Both the Law and the prophets describe it as a sign between God and Israel: "It [is] a sign between me and the children of Israel for ever" (Exodus 31:17); "I gave them my sabbaths, to be a sign between me and them" (Ezekiel 20:12). These are the Sabbatarians' strongest texts. They show that the Sabbath was real, holy and given by God. They also show whom it was given to, and what it was a sign of.

What the New Testament does with it

Jesus kept the Sabbath: "as his custom was, he went into the synagogue on the sabbath day" (Luke 4:16). He also claimed authority over it. "The sabbath was made for man, and not man for the sabbath: Therefore the Son of man is Lord also of the sabbath" (Mark 2:27-28). Paul preached in synagogues on Sabbaths (Acts 13:14; 17:2) because that was where the audience was, not because Christians gathered then for the Eucharist.

The apostolic letters then speak directly. "Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath [days]: Which are a shadow of things to come; but the body [is] of Christ" (Colossians 2:16-17). Adventist interpreters answer that these are the ceremonial sabbaths of the festivals, not the weekly one; but Paul's list (festival, new moon, sabbath) mirrors the Old Testament sequence of "her feast days, her new moons, and her sabbaths" (Hosea 2:11), where "sabbaths" most naturally includes the weekly day, and a shadow whose body is Christ is not a standing commandment. "One man esteemeth one day above another: another esteemeth every day [alike]. Let every man be fully persuaded in his own mind" (Romans 14:5) cannot be squared with a universal law of one holy day. To Gentile converts who were taking up "days, and months, and times, and years," Paul says: "I am afraid of you, lest I have bestowed upon you labour in vain" (Galatians 4:10-11). Hebrews says that "there remaineth therefore a rest to the people of God" and that "he that is entered into his rest, he also hath ceased from his own works" (Hebrews 4:9-10), a rest entered in Christ.

At the Council of Jerusalem the apostles decided what to ask of Gentile Christians. "It seemed good to the Holy Ghost, and to us, to lay upon you no greater burden than these necessary things" (Acts 15:28), and the list that follows (idol meats, blood, strangled things, fornication) does not include the Sabbath. Jewish believers continued to keep the Law for a time ("how many thousands of Jews there are which believe; and they are all zealous of the law," Acts 21:20). For the wider argument that Paul did not abolish the Law but fulfilled it, see our article on Paul and the Law. {{strong: The New Testament does not impose the weekly Sabbath on Gentile Christians, and Paul calls sabbaths a shadow whose body is Christ.}}

The first day in the New Testament

All four Gospels place the Resurrection on the first day of the week (Matthew 28:1; Mark 16:2; Luke 24:1; John 20:1). John adds that "the same day at evening, being the first [day] of the week," Jesus came to the assembled disciples, and that "after eight days again his disciples were within, and Thomas with them" when He came again (John 20:19, 26). Acts 20:7 records that "upon the first [day] of the week, when the disciples came together to break bread, Paul preached unto them." Paul tells the Corinthians: "Upon the first [day] of the week let every one of you lay by him in store, as [God] hath prospered him" (1 Corinthians 16:2). John writes in Revelation 1:10: "I was in the Spirit on the Lord's day."

Weighed one by one, Acts 20:7 is a real gathering for the breaking of bread, but it is one meeting, and commentators debate whether Luke counted the day from sunset in the Jewish way (so that it was Saturday evening) or from the morning. First Corinthians 16:2 may describe a collection set aside at home, not an assembly. In Revelation 1:10 "the Lord's day" could in principle mean the eschatological Day of the Lord; its later use for Sunday is certain, but whether John already means it is argued. No single text proves that the apostolic Church gathered on the first day of every week. Together they make a consistent pattern: the Resurrection, two appearances to gathered disciples, a Eucharistic meeting and a weekly collection, all on the first day, and a name for the day, "the Lord's day," that Christians soon applied to it.

Before Constantine: the witnesses

The claim that Sunday worship began in the fourth century is easy to test. The following witnesses are all earlier than the law of 321.

• The Didache (dated between about AD 70 and 120): "But every Lord's day gather yourselves together, and break bread, and give thanksgiving after having confessed your transgressions, that your sacrifice may be pure" (14).¹ The Greek is compressed ("on the Lord's of the Lord") and translators supply the noun "day," which the context supports.
• Pliny the Younger (about 111-113), governor of Bithynia, reports that Christians "were accustomed to meet on a fixed day before dawn and sing responsively a hymn to Christ as to a god."² Pliny does not name the day, so this fits Sunday without proving it.
• Ignatius of Antioch (about 110) writes to the Magnesians of those "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."³ The text needs an honest note. The one Greek manuscript of this form of the letter reads "according to the Lord's life"; the old Latin translation lacks "life," and the standard editions (Lightfoot; Lake) follow it, reading "the Lord's day." The longer, later version makes "Lord's Day" explicit. The reading "life" still has defenders, so I treat this witness as probable, not certain.
• The Epistle of Barnabas (dated variously from the late first to the early second century): "we keep the eighth day with joyfulness, the day also on which Jesus rose again from the dead" (15).⁴
• Justin Martyr (about 155), writing to the emperor: "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 are read and the bread and wine are offered. He gives the reason: "Sunday is the day on which we all hold our common assembly, because it is the first day on which God ... made the world; and Jesus Christ our Saviour on the same day rose from the dead."⁵

{{strong: Christians gathered for the Eucharist on the first day of the week, called the Lord's day, by the mid-second century at the latest and probably by its start, in several regions and independent writers.}} For Ignatius and Justin in more detail, see our article on Ignatius, our article on Justin and our article on the Didache.

What Constantine actually did

On March 7, 321, Constantine decreed (Codex Justinianus 3.12.2): "On the venerable Day of the Sun let the magistrates and people residing in cities rest, and let all workshops be closed. In the country, however, persons engaged in agriculture may freely and lawfully continue their pursuits."⁶ This is a civil rest law, framed in the language of the "day of the Sun." It does not mention worship, Christ or the Church, and it exempted farmers (for the wider "Constantine invented it" story, see our article on Constantine). It could not have created Sunday worship, because Christians were gathering on that day two centuries earlier. What it did was give the existing Christian custom the support of the state.

The Council of Laodicea, a regional council of the fourth century whose date is debated (the NPNF editor, following Hefele, places it between 343 and 381), speaks in its Canon 29 about both days: "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."⁷ This late, local canon shows the fourth-century Church treating Sabbath rest as Judaizing; it is not the origin of the Sunday practice. {{strong: Constantine's law of 321 was a civil day of rest and did not introduce Christian Sunday worship, which is attested two centuries earlier.}}

The Sabbatarian case at full strength

A fair statement of the Seventh-day Adventist and Sabbatarian position runs as follows. The fourth commandment stands in the Decalogue, which God wrote Himself and which Jesus said He had not come to destroy (Matthew 5:17). Nothing in the New Testament says in so many words that the seventh day has been replaced by the first. The change, they say, is a human tradition, and Protestants who keep Sunday while appealing to "the Bible alone" contradict themselves. Ellen White carried this to its end in The Great Controversy: "What then is the change of the Sabbath, but the sign, or mark, of the authority of the Roman Church, 'the mark of the beast'?" She supports this with a Catholic catechism that says "the church, instructed by Jesus Christ, and directed by the Spirit of God, has substituted Sunday for Saturday."⁸ The Adventist scholar Samuele Bacchiocchi made the case in a more careful historical form in From Sabbath to Sunday (1977): the move from Sabbath to Sunday, he argued, began early, in Rome, in the second century, under social, anti-Jewish and pagan pressures, rather than at the Resurrection.⁹ These arguments come from people who love Scripture, and they should not be caricatured.

The answer has five parts.

1. Scripture itself ties the Sabbath to Israel. Exodus 31:17 and Ezekiel 20:12 call it "a sign" between God and Israel, and Deuteronomy 5:15 grounds it in Israel's deliverance from Egypt. A sign of a covenant is fulfilled when the covenant is. Jesus said He came "to fulfil" the Law (Matthew 5:17), and Paul calls the Sabbath a shadow whose body is Christ (Colossians 2:17).
2. The apostles did decide the question, in Acts 15. The Sabbath is not among the requirements laid on Gentiles, and that silence is not an oversight in a chapter devoted to what Gentiles must keep.
3. The Church of the apostles gathered on the first day. White's argument requires that a later body changed the day. But the practice is attested in Syria, Asia Minor and Rome by about AD 110 to 155, long before any bishop of Rome could issue a command to the East. Ignatius was bishop of Antioch in Syria, the Didache probably comes from Syria, and Ignatius writes to churches in Asia Minor. If Rome had altered a divine commandment, the East would have to have followed in silence within a generation. The Orthodox position is that the apostolic Church set the day, not that Rome did; a Catholic writer's claim that "the church" changed the day does not make the papacy its author.
4. Bacchiocchi's thesis does not rescue the "mark" argument. Even on his dating the change began in the second century, which means that Constantine and the medieval papacy had nothing to do with its origin. That is a different theory from the one in The Great Controversy. And Justin, writing in Rome itself, gives the Resurrection as the reason for the Sunday gathering, which is hard to reconcile with a purely pagan or anti-Jewish origin.
5. The "mark of the beast" claim falls with its premise. White did not say that sincere Sunday-keepers bear the mark; she placed it in a future when Sunday observance is enforced by law, and the White Estate describes the scenario the same way: American Protestantism enforcing Sunday worship in cooperation with the papacy.¹⁰ But the whole scenario rests on her charge that Sunday is "a sabbath of her [Rome's] creating," and that is false: Rome did not invent the day, and the Church of the first centuries, including the martyrs, kept it. To make the Lord's Day the token of the beast is a grave error. We say this without doubting the sincerity of Adventist Christians.

Protestants who say "the Bible alone" and keep Sunday do face a real question, and Orthodoxy has the answer they lack: the Church that wrote and received the New Testament also handed down the Lord's Day, and the two cannot be separated (see the biblical case for Holy Tradition).

How the Orthodox Church keeps the days

The Church keeps Sunday as the weekly feast of the Resurrection. St Basil the Great writes that the church prays standing on that day, "not only because we rose with Christ ... but because the day seems to us to be in some sense an image of the age which we expect," and calls it "one and eighth," the day without evening.¹¹ The Council of Nicaea (325) ordered that "prayer be made to God standing" on the Lord's Day and in the days of Pentecost (Canon 20), and the Council in Trullo (692, Canon 90) repeated that "we are not to kneel on Sundays," from Saturday Vespers until Sunday evening.¹²

Saturday is not abandoned. The fifth-century Church historian Socrates reports that "almost all churches throughout the world celebrate the sacred mysteries on the sabbath of every week," with the exceptions of Alexandria and Rome.¹³ The Apostolic Constitutions, a Syrian church-order of about 375 to 380, instructs: "But keep the Sabbath, and the Lord's day festival; because the former is the memorial of the creation, and the latter of the resurrection," and names one Sabbath of the year as a fast, the Sabbath of the Lord's burial.¹⁴ That tradition survives in Orthodox practice. In Great Lent the Divine Liturgy is not served on weekdays, but it is served on Saturdays and Sundays (Laodicea, Canon 49, already says so); Saturday is the day the Church sets aside to commemorate the departed; and Great and Holy Saturday, on which Christ reposed in the tomb, the Church calls "the Blessed Sabbath" (see Holy Week and Pascha). Rest from needless work on the Lord's Day is a pious Christian custom, as Laodicea says, "if they can"; it is not the revival of a Mosaic law.

What we can say confidently

• The Sabbath of Exodus 20 was given to Israel as a sign of the covenant and a memorial of creation and the Exodus.
• The New Testament calls sabbaths "a shadow of things to come," leaves days to conscience, and does not impose the Sabbath on Gentile converts in Acts 15.
• All four Gospels date the Resurrection to the first day of the week, and Acts, 1 Corinthians and Revelation connect that day with gatherings and the "Lord's day."
• By about AD 110 to 155 the Didache, Ignatius, Barnabas and Justin attest Christian gatherings on the Lord's Day or Sunday, in several regions, all well before 321.
• Constantine's law of 321 was a civil rest law for the "day of the Sun" and did not create Christian Sunday worship.
• The Orthodox Church has always kept the Lord's Day as the weekly Pascha and has never abandoned Saturday's services and memorials.

What remains disputed

• Whether Acts 20:7 describes a Saturday-night or a Sunday gathering, and whether 1 Corinthians 16:2 describes an assembly.
• Whether Revelation 1:10 already means Sunday.
• Whether "sabbath" in Colossians 2:16 and the "days" of Romans 14:5 include the weekly Sabbath (Adventist interpreters say no).
• The reading of Ignatius, Magnesians 9 ("Lord's life" or "Lord's Day"), and the dates of the Didache and Barnabas.
• How far Jewish Christians kept the Sabbath beyond the apostolic age, and for how long.
• The exact date of the Council of Laodicea.

Conclusion

The Church gathers on the first day because that is the day Christ rose. The old covenant's seventh day pointed to a rest, and Christ is that rest. The Lord's Day is not a change imposed by an emperor or a bishop. It is the day on which the Church, from the beginning, broke bread and gave thanks, and the earliest witnesses say so in their own words. Sabbatarian Christians who ask whether we have departed from Scripture deserve this answer given with respect: we have kept what the apostles kept, and the Church has kept Scripture and the Lord's Day together. For more, see Why Orthodoxy.

Notes

1. The Didache 14, trans. M. B. Riddle, ANF vol. 7, https://www.newadvent.org/fathers/0714.htm. The date range "between 70 and 120" and the Greek ambiguity are from "Lord's Day," Wikipedia, https://en.wikipedia.org/wiki/Lord%27s_Day; "Didache," Wikipedia, https://en.wikipedia.org/wiki/Didache, reports that most scholars now place it in the first century and that its community may have been in Syria. Scripture is quoted from the King James Version (1769 text) as served by this site's Bible reader (https://honestapologist.com/api/bible/connections/texts?v=kjv), checked 2026-11-06.
2. Pliny the Younger, Letters 10.96, in the Internet History Sourcebooks, Fordham University (translation not named on the page), https://sourcebooks.fordham.edu/source/pliny1.asp. Pliny's term of office (111-113) is from the same page.
3. Ignatius, Epistle to the Magnesians 9, trans. Alexander Roberts and James Donaldson, ANF vol. 1, https://www.newadvent.org/fathers/0105.htm. The manuscript reading (the Medicean manuscript's kata kyriakēn zōēn), the Latin reading without "life" and the longer version are summarized in "Lord's Day," Wikipedia (note 1). Lightfoot's translation ("fashioning their lives after the Lord's day") is at https://ccel.org/ccel/lightfoot/fathers.ii.iv.html and Kirsopp Lake's Greek text (kata kyriakēn zōntes) at https://ccel.org/ccel/lake/fathers2.iii.ii.html. I did not open the manuscripts or the critical apparatus.
4. Epistle of Barnabas 15, trans. Roberts and Donaldson, ANF vol. 1, https://www.newadvent.org/fathers/0124.htm. Its date (between 70 and 135, before the Bar Kokhba revolt) is from "Epistle of Barnabas," Wikipedia, https://en.wikipedia.org/wiki/Epistle_of_Barnabas.
5. Justin Martyr, First Apology 67, trans. Marcus Dods and George Reith, ANF vol. 1, https://www.newadvent.org/fathers/0126.htm. "First Apology of Justin Martyr," Wikipedia, https://en.wikipedia.org/wiki/First_Apology_of_Justin_Martyr, dates it to 155-157 from its mention of a recent prefect of Egypt.
6. Constantine, edict dated the Nones (7th) of March 321, Codex Justinianus 3.12.2 (3.12.3 in older numbering), Latin text and translation in Philip Schaff, History of the Christian Church vol. 3, section 75, https://ccel.org/ccel/schaff/hcc3/hcc3.iii.x.ii.html. The edict's remaining clause explains the farm exemption (sowing and planting seasons); it does not mention worship.
7. Council of Laodicea, Canons 29 and 49, trans. Henry Percival, NPNF2 vol. 14, https://www.newadvent.org/fathers/3806.htm. The NPNF introduction reports dates of 365 (de Marca) and circa 363 (Pagi, Gothofred) and then follows Hefele in placing the synod "somewhere between the years 343 and 381."
8. Ellen G. White, The Great Controversy (1911 edition), pp. 447-449, checked against the page images published by the Ellen G. White Estate, https://media3.egwwritings.org/swf/en_GC/files/assets/seo/page378.html and page379.html (book pp. 448-449, including "a sabbath of her creating" and her statement that sincere Sunday-keepers are not yet marked); also reproduced at https://ellenwhite.info/us-in-prophecy-09.htm. White's dash before "the mark of the beast" is printed here as a comma. The catechism she quotes (the Catholic Catechism of Christian Religion) was not opened.
9. Samuele Bacchiocchi, From Sabbath to Sunday (Rome: Pontifical Gregorian University Press, 1977), read in the author's 1999 reprint (PDF at https://friendsofsabbath.org/Further_Research/Bacchiocchis%20Research/From%20Sabbath%20to%20Sunday.pdf): chapters 6-8 ("Rome and the Origin of Sunday," "Anti-Judaism in the Fathers," "Sun-Worship and the Origin of Sunday") and the conclusion that the Church of Rome "appears to have played a leading role." See also "Samuele Bacchiocchi," Wikipedia, https://en.wikipedia.org/wiki/Samuele_Bacchiocchi.
10. Ellen G. White Estate, "History of the Three Angels' Messages, the Mark of the Beast and Ellen G. White," https://whiteestate.org/about/issues/history-of-the-three-angels-messages-the-mark-of-the-beast-and-ellen-g-white/, which describes the Adventist view that the mark concerns a future enforcement of Sunday worship.
11. St Basil the Great, On the Holy Spirit 27.66, trans. Blomfield Jackson, NPNF2 vol. 8, https://www.newadvent.org/fathers/3203.htm.
12. First Council of Nicaea, Canon 20, trans. Henry Percival, NPNF2 vol. 14, https://www.newadvent.org/fathers/3801.htm; Council in Trullo, Canon 90, same translation, https://www.newadvent.org/fathers/3814.htm.
13. Socrates Scholasticus, Church History 5.22, trans. A. C. Zenos, NPNF2 vol. 2, https://www.newadvent.org/fathers/26015.htm.
14. Apostolic Constitutions 7.23, trans. James Donaldson, ANF vol. 7, https://www.newadvent.org/fathers/07157.htm; date (375-380) and Syrian provenance from "Apostolic Constitutions," Wikipedia, https://en.wikipedia.org/wiki/Apostolic_Constitutions. Present Orthodox practice: Orthodox Church in America, "3rd Saturday of Great Lent: Memorial Saturday," https://www.oca.org/saints/lives/2021/04/03/13-3rd-saturday-of-great-lent-memorial-saturday ("Saturday is the day which the Church has set aside for the commemoration" of the departed; the Divine Liturgy "cannot be served on weekdays during Great Lent"), and "Great and Holy Saturday," https://www.oca.org/saints/lives/2031/04/12/26-great-and-holy-saturday ("The Church calls this day the Blessed Sabbath"); Laodicea Canon 49 as in note 7.

Bibliography

Scripture and early Christian sources

• The Holy Bible, King James Version (1769 text).
• The Didache; Ignatius, To the Magnesians; Epistle of Barnabas. ANF vols. 1 and 7.
• Pliny the Younger, Letters 10.96-97.
• Justin Martyr, First Apology. ANF vol. 1.
• Basil the Great, On the Holy Spirit. NPNF2 vol. 8.
• Socrates Scholasticus, Church History. NPNF2 vol. 2.
• Councils of Nicaea (325), Laodicea and Trullo (692). NPNF2 vol. 14.
• Constantine's edict of 321, in Schaff, History of the Christian Church vol. 3.
• Apostolic Constitutions. ANF vol. 7.

Adventist and Sabbatarian sources

• White, Ellen G. The Great Controversy.
• Bacchiocchi, Samuele. From Sabbath to Sunday.
• Ellen G. White Estate, "History of the Three Angels' Messages, the Mark of the Beast and Ellen G. White."

Editions and Orthodox sources

• Lightfoot, J. B., trans. The Apostolic Fathers; Lake, Kirsopp, ed. The Apostolic Fathers (Loeb). Ignatius, Magnesians 9.
• Orthodox Church in America, "Memorial Saturday" and "Great and Holy Saturday" (oca.org).