Christians don’t keep the seventh-day Sabbath but Sunday instead. Why? Christians belong to the New Testament and the New Creation in the New Adam, who is Jesus Christ. We do not belong to the old creation and old sabbath.

Hebrews 8:13: “In speaking of a new covenant, he makes the first one obsolete.”

“Finally, He says to them: ‘Your new moons and your Sabbaths I cannot endure.’ You see what He means: it is not the present Sabbaths that are acceptable to Me, but the one which I have made, when, giving rest to all things, I shall make the beginning of an eighth day, that is, the beginning of another world.

Wherefore also we keep the eighth day with joyfulness, the day on which Jesus rose from the dead, and after He had appeared, ascended into the heavens.”

Epistle of Barnabas 15:8–9 (Ante-Nicene Fathers [ANF], Vol. 1, p. 147).

Why Christians Worship on Sunday Instead of Saturday

From a Christian viewpoint, the shift from worshiping on Saturday (the Jewish Sabbath) to Sunday (Christian Lord’s Day) is a profound theological and historical development rooted in the New Testament, early Church tradition, and the fulfillment of the Old Covenant in Christ.

Today, I’ll explore why Christians do not communal worship on Saturday but instead on Sunday, drawing on Sacred Scripture—particularly the New Testament—and the writings of early Church Fathers like Ignatius of Antioch and the author of the Epistle of Barnabas. We now belong to the New Testament and the New Creation in the New Adam, who is Jesus Christ.

Christ’s Resurrection and the Lord’s Day

The New Testament provides the foundational basis for Sunday worship, emphasizing Christ’s resurrection as the defining event that transforms the rhythm of Christian life. In the Gospel of Matthew, Jesus rises on “the first day of the week” (Matthew 28:1), which corresponds to Sunday in the Jewish reckoning of days beginning at sundown. Similarly, Mark 16:2 states, “And very early on the first day of the week, when the sun had risen, they went to the tomb,” and Luke 24:1 echoes, “But on the first day of the week, at early dawn, they went to the tomb.” John 20:1 reinforces this: “Now on the first day of the week Mary Magdalene came to the tomb early.” This consistent testimony across the Gospels identifies Sunday as the day of Christ’s triumph over death, a pivotal moment that Catholics see as inaugurating a new creation.

New Testament Witness

This resurrection significance extends to early Christian practice. Acts 20:7 records, “On the first day of the week, when we were gathered together to break bread, Paul talked with them.” The phrase “break bread” is widely understood in Catholic tradition as a reference to the Eucharist, the central act of worship. This gathering on Sunday reveals a shift from the Jewish Sabbath (Saturday) to a new day of Eucharistic worship tied to Christ’s rising. Likewise, 1 Corinthians 16:2 advises, “On the first day of every week, each of you is to put something aside and store it up,” indicating a regular Sunday collection during worship, further evidencing its liturgical prominence.

Revelation 1:10 adds a theological layer: “I was in the Spirit on the Lord’s Day.” Though not explicitly cited as “Sunday,” early Christians interpreted “the Lord’s Day” (kyriakē hēmera) as the first day of the week, commemorating Christ’s resurrection. The Didache (c. AD 70–120) and later Fathers confirm this usage. Thus, the New Testament establishes Sunday as the day when Christians gathered to celebrate the Eucharist and honor Christ’s victory, distinguishing it from the Jewish Sabbath.

Fulfillment of the Sabbath in Christ

The New Testament views the Sabbath—a commandment to rest on the seventh day (Exodus 20:8–11)—as part of the old creation and old covenant, fulfilled and transformed by Christ in the New Covenant.

Colossians 2:16–17 states, “Therefore let no one pass judgment on you in questions of food and drink, or with regard to a festival or a new moon or a Sabbath. These are a shadow of the things to come, but the substance belongs to Christ.” Paul here identifies the Sabbath as a “shadow,” a prefigurement of the spiritual rest found in Christ, not a perpetual obligation for Christians.

Hebrews 4:9–10 deepens this: “So then, there remains a Sabbath rest for the people of God, for whoever has entered God’s rest has also rested from his works as God did from his.” This “Sabbath rest” is eschatological, realized in Christ’s redemptive work, not tied to a specific day.

The Council of Jerusalem (Acts 15) further supports this shift. When debating whether Gentile converts must follow Mosaic Law, the apostles, led by Peter, ruled that only minimal requirements (e.g., abstaining from idolatry and immorality) were necessary, omitting Sabbath observance (Acts 15:28–29). This decision, authoritative for Christians, signals that the ceremonial laws, including the Saturday Sabbath, do not bind Christians.

Early Church Fathers: Ignatius of Antioch

Ignatius of Antioch (d. c. AD 108), a disciple of the Apostle John, provides early testimony to the abandonment of Saturday worship in favor of Sunday. In his Epistle to the Magnesians 9:1, he writes,

“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… how shall we be able to live apart from Him?” (ANF, Vol. 1, p. 62).

Ignatius contrasts the Jewish Sabbath with the Lord’s Day (Sunday), linking the latter to Christ’s resurrection as the source of new life. His phrase “no longer observing the Sabbath” explicitly rejects Saturday worship for Christians, emphasizing a theological shift rooted in Easter.
Ignatius’ context is anti-Judaizing: he warns against Christians reverting to Jewish practices, which he sees as denying Christ’s grace (Magnesians 8:1: “If we still live according to the Jewish law, we acknowledge that we have not received grace”). For Christians, Ignatius’ witness, as an Apostolic Father, carries weight, reflecting apostolic tradition that Sunday supplants Saturday as the day of worship.

Early Church Fathers: Epistle of Barnabas

The Epistle of Barnabas (c. AD 70–132), though not canonical, offers a sharp critique of literal Sabbath-keeping, reinforcing the Catholic view. In Barnabas 15:8–9, the author declares,

“Finally, He says to them: ‘Your new moons and your Sabbaths I cannot endure.’ You see what He means: it is not the present Sabbaths that are acceptable to Me, but the one which I have made, when, giving rest to all things, I shall make the beginning of an eighth day, that is, the beginning of another world. Wherefore also we keep the eighth day with joyfulness, the day on which Jesus rose from the dead” (ANF, Vol. 1, p. 147).

Citing Isaiah 1:13, the author argues that God rejects the Jewish Sabbath, reinterpreting it as an eschatological rest fulfilled in Christ. The “eighth day” (Sunday, following the seventh-day Sabbath) symbolizes this new era, aligning with resurrection theology.

Christians observe this as evidence of an early Christian consensus that Saturday worship is obsolete, replaced by Sunday’s celebration of the “new world” begun in Christ. While Barnabas is polemical and not magisterial, its influence on early theology underscores the shift away from Judaizing practices.

Theological Rationale: Sunday as the Day of the New Creation

Christian doctrine ties Sunday worship to the concept of a “new creation.” Just as God rested on the seventh day after creating the world (Genesis 2:2–3), Christ’s resurrection on the first day marks the renewal of a new creation. Christ fulfills the Sabbath’s purpose—rest and communion with God—in a new context, as Christ’s victory over sin and death (Romans 6:4) surpasses the old order.

The Church Fathers amplify this. Ignatius’ “life has sprung up again” (Magnesians 9) and Barnabas’ “beginning of another world” (15:8) echo 2 Corinthians 5:17: “If anyone is in Christ, he is a new creation.” Sunday thus becomes the day when Catholics celebrate this renewal through the Mass, which re-presents Christ’s sacrifice and resurrection.

Traditional Witness and Authority

Historically, Christian Sunday communal worship emerged early, as seen in Acts 20:7 and 1 Corinthians 16:2, and was codified by Church authority. The Council of Laodicea (c. AD 363–364), Canon 29, later declared, “Christians must not judaize by resting on the Sabbath, but must work on that day… preferring in honor the Lord’s Day” (NPNF, Series 2, Vol. 14, p. 148). This reflects a Catholic reliance on apostolic tradition and the Magisterium to interpret Scripture, per 2 Thessalonians 2:15: “Stand firm and hold to the traditions that you were taught by us.”

Conclusion for Christians

Christians worship on Sunday, not Saturday, because the New Testament establishes it as the day of Christ’s resurrection (Matthew 28:1, Acts 20:7), fulfilling the Sabbath’s shadow (Colossians 2:16–17) in a New Covenant of grace (Acts 15). Fathers such as Ignatius of Antioch confirm this shift, rejecting Sabbath observance for the Lord’s Day (Magnesians 9:1), while Barnabas redefines rest as an eschatological reality celebrated on the “eighth day” (15:8–9). Theologically, Sunday honors the new creation in Christ, a truth the Catholic Church, guided by apostolic authority, has upheld since the resurrection of Christ. For Christians, this is not a rejection of the Sabbath’s sanctity but its transformation into a higher celebration of redemption, lived out each Sunday in the Eucharist.

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