Sabbatarianism advocates the observation of the Sabbath in Christianity, in keeping with the Ten Commandments.

The observance of Sunday as a day of worship and rest is a form of first-day Sabbatarianism, a view which was historically heralded by nonconformist denominations, such as Congregationalists, Presbyterians, Methodists, Moravians, Quakers and Baptists, as well many Episcopalians. Among Sunday Sabbatarians (First-day Sabbatarians), observance of the Lord's Day often takes the form of attending the Sunday morning service of worship, receiving catechesis through Sunday School (often referred to as Sabbath school), performing acts of mercy (such as evangelism, visiting prisoners in jails and seeing the sick at hospitals), and attending the Sunday evening service of worship, as well as refraining from Sunday shopping, servile work, playing sports, viewing the television, and dining at restaurants. The impact of first-day Sabbatarianism on Western culture is manifested by practices such as Sunday blue laws.

Seventh-day Sabbatarianism is a movement that generally embraces a literal reading of the Sabbath commandment that provides for both worship and rest on Saturday, the seventh day of the week. Judaism has observed a sabbath on the seventh day since antiquity, following the creation account in Genesis 2 which unambiguously states that God blessed and sanctified the seventh day, having rested on the seventh day from all his creation which God had made to do. Seventh Day Baptists leave most other Sabbath considerations of observance to individual conscience. The Seventh-day Sabbatarian Adventists (Seventh-day Adventist Church, Davidian Seventh-day Adventists, Church of God (Seventh Day), and others) have similar views, but maintain the original, scriptural duration as Friday sunset through Saturday sunset. The Orthodox Tewahedo Churches in Ethiopia and Eritrea observe the seventh-day Sabbath, as well as Sunday as the Lord's Day. Likewise, the Coptic Church, another Oriental Orthodox body, "stipulates that the seventh-day Sabbath, along with Sunday, be continuously regarded as a festal day for religious celebration."

Its historical origins lie in early Christianity, later in the Eastern Church and Irish Church, and then in Puritan Sabbatarianism, which delineated precepts for keeping Sunday—the Lord's Day—holy in observance of Sabbath commandment principles.

Non-Sabbatarianism is the view opposing all Sabbatarianism, declaring Christians to be free of mandates to follow such specific observances. It upholds the principle in Christian church doctrine that the church is not bound by such law or code, but is free to set in place and time such observances as uphold Sabbath principles according to its doctrine: to establish a day of rest, or not, and to establish a day of worship, or not, whether on Saturday or on Sunday or on some other day. It includes some nondenominational churches.

History

Theological background Most Christian churches, including the Roman Catholic Church, Methodist Churches and Reformed Churches, have traditionally held that law in the Old Covenant has three components: ceremonial, moral, and civil. They teach that while the ceremonial and civil (judicial) laws have been abolished, the moral law as contained in the Ten Commandments still continues to bind Christian believers.Summa Theologica, I-II, q. 100 Among these Ten Commandments, which are believed by Jews and Christians to be written by the finger of God, is "Remember the sabbath day, to keep it holy."

According to the New Testament, after the resurrection of Jesus he appeared to his disciples on the first day of the week (, , , ), the Holy Spirit was sent to the Church on the first day of the week (Pentecost Sunday), the disciples celebrated the Eucharist and took up collections on the first day of the week (, ); in addition the first day of the week is referred to as the Lord's Day in —these findings, for Christians, served as the divine institution of the Lord's Day as a fulfillment of the Jewish Shabbat, a change that these Christians believed was foreshadowed in . The Apostolic Constitutions (ca. 380), in Section II, reveals that the early Church kept both the seventh-day Sabbath, observed on Saturday, as well as the Lord's Day, celebrated on the first-day (Sunday): "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." Section VII reemphasizes this: The Didache is commonly said to command believers to "Gather together each Sunday, break bread and give thanks, first confessing your sins, that your sacrifice may be pure," but the Didache never commands believers to assemble on a specific day. Unlike Didache 8, which explicitly names fasting days (δευτέρα and πέμπτη), chapter 14 simply reads κατὰ κυριακὴν δὲ κυρίου, which in context refers to the Lord's Eucharist or "the Lord's Thanksgiving," not "the Lord's Day." Some scholars argue that translating it as "the Lord's Day" reflects later Christian usage at the time the manuscript was transmitted rather than the immediate context of the passage. This also fits other early evidence that many churches gathered on both the Sabbath and the first day of the week, making it unlikely that the Didache intended to prescribe only one day of assembly, but per the Lord's inspiration. It was upheld in the fourth century by the ancient Church of the East, as well as in the sixth century by the Celtic Churches. Gregory of Nyssa, a fourth century Church Father, implored the faithful to observe both the seventh-day Sabbath and the Lord's Day: "With what eyes do you regard the Lord's Day, you who have desecrated the Sabbath? Do you know that these two days are related, that if you wrong one of them, you will stumble against the other?" Nevertheless, Johann Lorenz von Mosheim stated that the practice of observing both the Hebrew Sabbath and the Lord's Day was principally observed in those congregations that were made up of Jewish converts to Christianity and gradually faded away; on the other hand, the observance of the Lord's Day was characteristic of all Christian assemblies.

Differences between Jewish and Christian observance In distinguishing the observances performed on the Christian Sabbath from those performed on the Jewish Sabbath, Jonathan Edwards wrote:

Views of Church Fathers and Reformers As early as the second century, Irenaeus, who was a disciple of Polycarp, himself a disciple of John the Apostle, "On the Lord’s day every one of us Christians keep the Sabbath, meditating on the law, and rejoicing in the works of God." Writing in the fourth century, the early Church Father, Eusebius, taught that for Christians, "the sabbath had been transferred to Sunday". This view held by Eusebius, particularly his "interpretation of Psalm 91 (ca. 320) greatly influenced the ultimate transfer of sabbath assertions and prohibitions to the first day of the week." In "the fourth and fifth centuries theologians in the Eastern church were teaching the practical identity of the Jewish sabbath and the Christian Sunday." Saint Cæsarius of Arles (470-543) reiterated the view that "the whole glory of the Jewish Sabbath had been transferred onto Sunday, so that Christians had to keep it holy in the same way as the Jews had their own day of rest." The Council of Elvira, in AD 300, declared that individuals who failed to attend church for three Sundays in a row should be excommunicated until they repented of their sin. Tendencies towards Sabbatarianism began to resurface very early in the Reformation (early 16th century), causing some of the first Protestants, Luther and Calvin among them, to deny the need for legal codes and accept the non-Sabbatarian principles long established in Christianity.

Observance of the Sabbath in Oriental Christianity In Oriental Christianity, however, the Sabbath always retained importance, particularly leading to controversy within the Ethiopian Orthodox Tewahedo Church. In the fourteenth century, the monk Abba Ewostatewos and his supporters, mostly based in mountainous areas of northwest Ethiopia found themselves in controversy with southern monks over strict observance of the Sabbath; "the Sabbatarian controversy divided the kingdom during the fourteenth and fifteenth centuries." Zara Yaqob, the king, eventually "decreed that the Sabbatarian teaching of the northern monks become the position of the church". This "Sabbatarian" teaching was not the innovation of Ewostatewos but was based on the historic teaching of the Apostolic Constitutions and was not a controversy within the Coptic Orthodox Church up until that point. This observance is not considered a Judaizing practice, as the Confession of emperor Saint Gelawdewos summarizes: "we do not honour it as the Jews do... but we so honour it that we celebrate thereon the Eucharist and have love-feasts, even as our Fathers the Apostles have taught us in the Didascalia".

Observance of the Sabbath in Western Christianity In the Roman Catholic Church, Church Councils and imperial edicts "sought to restrict various activities on this day Sunday, especially public amusements in the theater and circus." Abstention from sin, in the eyes of Saint Augustine of Hippo (354–430), meant Sabbath rest from servile work on Sunday.

Many Protestant denominations, such as the Presbyterian and Methodist Churches, observe Sunday as the Christian Sabbath. The Presbyterian Church of Scotland promoted first-day Puritan Sabbatarian practices. In addition, first-day Sabbatarianism is historically heralded by nonconformist denominations, such as Congregationalists and Presbyterians, as well as Methodists and Baptists.

The essence of first-day Sabbatarianism, named for the Sabbath, is that it upholds the idea that Christians are bound to keep a specific code of conduct in relation to the principal day of Christian worship, or a day of rest, or both. The first-day, Puritan Sabbatarians constructed their code from their understanding of moral obligations following from their interpretation of "natural law", first defined in writings of Thomas Aquinas. Not seeking to re-establish Mosaic Law or Hebrew Sabbath practices, their connection to Judaizing was limited to the use of a legal code by which Christians might be judged.

With unwavering support by mainstream Christian denominations, Sabbatarian organizations were formed, such as the Lord's Day Alliance (founded as the American Sabbath Union) and the Sunday League of America, following the American Civil War, to preserve the importance of Sunday as the Christian Sabbath. Founded in 1888, the Lord's Day Alliance continues to state its mission as to "encourage all people to recognize and observe a day of Sabbath rest and to worship the risen Lord Jesus Christ, on the Lord’s Day, Sunday". The Board of Managers of the Lord's Day Alliance is composed of clergy and laity from Christian churches, including Baptist, Catholic, Episcopalian, Friends, Lutheran, Methodist, Non-Denominationalist, Orthodox, Presbyterian, and Reformed traditions. The Woman's Christian Temperance Union also supports first-day Sabbatarian views and worked to reflect these in the public sphere. In Canada, the Lord's Day Alliance (renamed the People for Sunday Association of Canada) was founded there and it lobbied successfully to pass in 1906 the Lord's Day Act, which was not repealed until 1985. A Roman Catholic Sunday league, the Ligue du Dimanche was formed in 1921 to promote first-day sabbatarian restrictions in Quebec, especially against movie theaters. Throughout their history, first-day Sabbatarian organizations, such as the Lord's Day Alliance, have mounted campaigns, with support in both Canada and Britain from labour unions, with the goals of preventing secular and commercial interests from hampering freedom of worship and preventing them from exploiting workers.