"The fourth commandment says the seventh day. Saturday is the seventh day. So why do you go to church on Sunday?" Fair question. Let's open the Bible.
Short answer: Christians worship on Sunday because Jesus rose on "the first day of the week," and from the beginning His Church gathered on that day, "the Lord's day." The Sabbath was a sign of God's covenant with Israel, a shadow fulfilled in Christ. The duty to set apart time for God remains; its Christian form is Sunday.
Key verses on the Lord's Day
- "On the first day of the week when we gathered to break bread" (Acts 20:7)
- "On the first day of the week each of you should set aside and save" (1 Corinthians 16:2)
- "I was caught up in spirit on the Lord's day" (Revelation 1:10)
- "These are shadows of things to come; the reality belongs to Christ" (Colossians 2:17)
- "When he had risen, early on the first day of the week" (Mark 16:9)
- "On the evening of that first day of the week... Jesus came and stood in their midst" (John 20:19)
Scripture quotations are from the New American Bible, Revised Edition (NABRE), © 2010, 1991, 1986, 1970 Confraternity of Christian Doctrine, Washington, D.C. Used by permission. All rights reserved.
What Catholics Actually Teach
The Church honors the Sabbath: Jesus "never fails to respect the holiness of this day" (CCC 2173). But Sunday is the day of the Resurrection. As the "first day," it "recalls the first creation"; as the "eighth day" following the sabbath, it "symbolizes the new creation ushered in by Christ's Resurrection" (CCC 2174).
So "for Christians its ceremonial observance replaces that of the sabbath," and "Sunday fulfills the spiritual truth of the Jewish sabbath and announces man's eternal rest in God" (CCC 2175). The commandment's moral core stays: to give God "an outward, visible, public, and regular worship" (CCC 2176).
What Catholics do not teach:
- That the Ten Commandments are abolished. Keeping the Lord's day holy still binds us.
- That Saturday is Sunday. Sunday "is expressly distinguished from the sabbath which it follows chronologically every week" (CCC 2175).
- That Sunday began with Constantine. Christians gathered on Sunday long before him, as you will see below.
The Biblical Case
1. Jesus rose on the first day of the week
All four Gospels stress the day (Matthew 28:1; Mark 16:2; Luke 24:1; John 20:1). St. Mark says it plainly: "When he had risen, early on the first day of the week, he appeared first to Mary Magdalene" (Mark 16:9). The new creation began on the day the first creation began.
2. The risen Jesus meets His disciples on Sundays
"On the evening of that first day of the week... Jesus came and stood in their midst" (John 20:19). Then: "Now a week later his disciples were again inside and Thomas was with them. Jesus came" (John 20:26). Counted the Jewish way, that is the following Sunday.
3. The apostolic Church gathers on the first day
"On the first day of the week when we gathered to break bread, Paul spoke to them" (Acts 20:7). The NABRE note says the first day was "apparently chosen originally by the Jerusalem community for the celebration of the liturgy of the Eucharist in order to relate it to the resurrection of Christ." St. Paul also has Corinth set aside its collection "on the first day of the week" (1 Corinthians 16:2), as he "ordered the churches of Galatia" (16:1). Sunday was already the churches' regular day.
4. St. John calls it "the Lord's day"
"I was caught up in spirit on the Lord's day" (Revelation 1:10). Not "the sabbath," but a new Christian name, which the earliest Christian writers use for Sunday (see below; CCC 2174).
5. The Sabbath was a covenant sign and a shadow
God gave the Sabbath to Israel as "the sign between you and me throughout the generations" (Exodus 31:13): "Between me and the Israelites it is to be an everlasting sign" (31:17).
St. Paul tells Gentile believers: "Let no one, then, pass judgment on you in matters of food and drink or with regard to a festival or new moon or sabbath. These are shadows of things to come; the reality belongs to Christ" (Colossians 2:16–17).
6. The true rest is in Christ
"Therefore, a sabbath rest still remains for the people of God. And whoever enters into God's rest, rests from his own works as God did from his" (Hebrews 4:9–10). The Sabbath's meaning, rest in God, is fulfilled in the One who is "lord even of the sabbath" (Mark 2:28).
Objections Answered
(a) "The Sabbath is in the Ten Commandments, and God made it holy at creation."
At its strongest: "Remember the sabbath day—keep it holy... the seventh day is a sabbath of the LORD your God" (Exodus 20:8–11). The reason is creation, and before Israel existed, "God blessed the seventh day and made it holy" (Genesis 2:3). The other nine commandments are moral law. Why would one be temporary?
Answer: The commandment's moral core, regular public worship of the Creator, is permanent (CCC 2176). Its seventh-day form was the covenant sign with Israel (Exodus 31:13–17). The apostles bound Gentile Christians only to "these necessities" (Acts 15:28–29), and the Sabbath is not among them. St. Paul calls the sabbath a "shadow" (Colossians 2:17) and worries over believers "observing days, months, seasons, and years" (Galatians 4:10). The first creation was crowned on the seventh day; the new creation began on the eighth, when Christ rose (CCC 2174).
(b) "Jesus and Paul kept the Sabbath, and Jesus did not abolish the law."
At its strongest: "Do not think that I have come to abolish the law or the prophets. I have come not to abolish but to fulfill" (Matthew 5:17). St. Paul, "following his usual custom," reasoned in the synagogue "for three sabbaths" (Acts 17:2).
Answer: Jesus kept the Sabbath because He lived under the Law before the New Covenant was sealed in His blood. St. Paul went to synagogues on the Sabbath to preach Christ where Jews gathered to hear Scripture. When Acts shows the Church gathering "to break bread," it is "on the first day of the week" (Acts 20:7). And "fulfill" is the point: the shadow gives way to "the reality" (Colossians 2:17).
(c) "The Catholic Church, or Constantine, changed the day."
At its strongest: Many Adventists hold that Sunday worship was a later human tradition, imposed by Rome or by Constantine's Sunday law of AD 321.
Answer: Catholics do believe Christ gave His Church real authority (see Is the Papacy Biblical?). But Sunday worship is already in the New Testament (Acts 20:7; 1 Corinthians 16:2; Revelation 1:10), and second-century Christians describe it plainly. Constantine's law made an existing Christian practice a civil day of rest. (See Did the Catholic Church Change the Sabbath to Sunday?)
(d) "The Sabbath is an 'everlasting covenant,' kept even in the new earth, and Colossians 2 means only the ceremonial sabbaths."
At its strongest: God called the Sabbath "an everlasting covenant" (Exodus 31:16). Isaiah foresees it in the world to come: "From new moon to new moon, and from sabbath to sabbath, All flesh shall come to worship before me" (Isaiah 66:22–23). So the "sabbath" that Colossians 2:16 calls a shadow must be the yearly ceremonial sabbaths, not the weekly seventh day written by God's finger.
Answer: Look at St. Paul's list: "a festival or new moon or sabbath" (Colossians 2:16). That is the Old Testament's standard sequence of yearly, monthly and weekly holy days, as in Hosea: "her festivals, her new moons, her sabbaths" (Hosea 2:13). The yearly feasts are already named as "festival"; the weekly Sabbath is the one left to name.
"Everlasting" proves too much. Circumcision was given as "an everlasting covenant" (Genesis 17:13), and Aaron's sons received "a perpetual priesthood throughout all future generations" (Exodus 40:15). Yet "Circumcision means nothing, and uncircumcision means nothing" (1 Corinthians 7:19), and "When there is a change of priesthood, there is necessarily a change of law as well" (Hebrews 7:12). The covenant signs are everlasting in what they signify, fulfilled in Christ, not in their Old Covenant form. And Isaiah 66:23 names new moons alongside sabbaths; no Adventist keeps the new moons. The prophet pictures unbroken worship in God's new creation, which Hebrews calls the "sabbath rest" that "still remains for the people of God" (Hebrews 4:9).
The earliest Christians read it exactly this way. The Letter of Barnabas hears God saying, "Your present Sabbaths are not acceptable to Me," and answers: "we keep the eighth day with joyfulness." St. Ignatius describes converts "brought up in the ancient order of things" who are "no longer observing the Sabbath."
The Early Church Agrees
- The Didache (late first or early second century): "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" (ch. 14).
- St. Ignatius of Antioch (Letter to the Magnesians, c. AD 107) speaks of those "brought up in the ancient order of things" who now live "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" (ch. 9).
- The Letter of Barnabas (probably early second century): "we keep the eighth day with joyfulness, the day also on which Jesus rose again from the dead" (ch. 15).
- St. Justin Martyr (First Apology, c. AD 155): "And on the day called Sunday, all who live in cities or in the country gather together to one place" ... "Sunday is the day on which we all hold our common assembly, because it is the first day on which God, having wrought a change in the darkness and matter, made the world; and Jesus Christ our Saviour on the same day rose from the dead" (ch. 67).
Conclusion
Adventists are right that God's day matters and worship is never optional. The question is which day Christ made His own. He rose on the first day, met His disciples on the first day, and His apostles gathered to break bread on the first day. Within a generation of St. John, Christians from Syria to Rome called it "the Lord's day" and gathered for the Eucharist. That is not a later corruption of the apostolic Church. It is the apostolic Church, the Catholic Church.
If you keep the seventh day out of love for God's word, we respect that love. Read Colossians 2 and Hebrews 4 again, and ask what the first Christians meant by "the Lord's day." The Sabbath pointed to a rest only Christ gives.
Come home. The Lord's day that the apostles kept from the morning of the Resurrection is still kept today in the Catholic Church, at every Sunday Mass. Christ promised, "upon this rock I will build my church" (Matthew 16:18), and His Church never fell away or disappeared. It is the Catholic Church, governed by the successor of St. Peter and the bishops in communion with him. "It is through Christ's Catholic Church alone, which is the universal help toward salvation, that the fullness of the means of salvation can be obtained" (CCC 816). We invite you to come and see the Church Christ founded, and to enter her.
Your next step: Come to Mass this Sunday at your local Catholic church. You can find one near you at MassTimes.org. Everyone is welcome; if you're not yet Catholic, pray with us but don't receive Communion yet. When you're ready to become Catholic, call the parish office and ask about OCIA, the Order of Christian Initiation of Adults. They will walk you through every step. Read our guide: How Do I Become Catholic? Not ready yet? Get our free pocket guide below and keep learning.
FAQ
Is Sunday just the Sabbath moved to a new day? Not exactly. "The sabbath, which represented the completion of the first creation, has been replaced by Sunday which recalls the new creation inaugurated by the Resurrection of Christ" (CCC 2190).
Is it wrong to worship on Saturday? Praying on any day is good, and the New Testament does not bind Christians to the seventh day (Colossians 2:16). But the question is not only which day; it is which Church. The Catholic Church keeps the Lord's day, the day of the Resurrection, as the apostles did. For Catholics, Saturday worship does not replace the Lord's day. "On Sundays and other holy days of obligation the faithful are bound to participate in the Mass," and that precept is met by a Mass "celebrated anywhere in a Catholic rite either on the holy day or on the evening of the preceding day" (CCC 2180). Catholics must keep it "unless excused for a serious reason" (CCC 2181).
Why can Catholics attend Sunday Mass on Saturday evening? The Church allows the Sunday obligation to be met "on the evening of the preceding day" (CCC 2180), echoing the biblical custom of counting a day from evening.
Sources
Scripture (NABRE, bible.usccb.org): Genesis 2:2–3; Genesis 17:13; Exodus 20:8–11; Exodus 31:13–17; Exodus 40:15; Isaiah 66:22–23; Hosea 2:13; Matthew 5:17; Matthew 16:18; Matthew 28:1; Mark 2:27–28; Mark 16:2, 9; Luke 24:1; John 20:1, 19, 26; Acts 15:28–29; Acts 17:2; Acts 20:7 (with NABRE note); 1 Corinthians 7:19; 1 Corinthians 16:1–2; Galatians 4:10; Colossians 2:16–17; Hebrews 4:9–10; Hebrews 7:12; Revelation 1:10.
Catechism of the Catholic Church (vatican.va): 816; 2173; 2174, 2175, 2176, 2180, 2181; 2190.
Church Fathers (newadvent.org): Didache 14 (ANF vol. 7); St. Ignatius of Antioch, Letter to the Magnesians 9 (ANF vol. 1); Letter of Barnabas 15 (ANF vol. 1); St. Justin Martyr, First Apology 67 (ANF vol. 1, ccel.org).