The Council of Trent:
The Argument That Exposed Sola Scriptura’s Weakness

In the sixteenth century, the Protestant Reformation shook the foundations of Western Christendom. Martin Luther nailed his Ninety-Five Theses to the door of the Wittenberg church in 1517, and the rallying cry of the Reformers rang out across Europe: Sola Scriptura — Scripture alone is the supreme authority for Christian faith and practice. It was a bold, courageous stand against centuries of accumulated tradition.

But the Roman Catholic Church had a devastating counter-argument — and it came from an unexpected place: the Protestants' own calendar.

The Council of Trent and the Archbishop’s Challenge

The Council of Trent (1545–1563) was the Catholic Church’s formal response to the Protestant Reformation. In one of its sessions in 1562, Archbishop Gaspare de Fosso of Reggio delivered a speech that has echoed through Protestant history ever since. He pointed out a glaring inconsistency in the Protestant position: if Sola Scriptura were truly the rule of faith, then Protestants should be worshipping on the seventh-day Saturday — not Sunday.

“The Protestants claim to stand by the Bible alone, yet they observe Sunday, for which there is no Scriptural authority, but only the tradition of the Church. By observing Sunday, they acknowledge the power of the Catholic Church to institute holy days and to command obedience under sin — and this same Church has transferred the obligation from Saturday to Sunday.”

— Archbishop Gaspare de Fosso, Council of Trent, 1562 (paraphrased from the historical record)

The argument was simple and surgical: Sunday is not in the Bible. The New Testament contains no command to transfer worship from the seventh day to the first day. The change was made by the authority of the Roman Catholic Church — and every Protestant who observes Sunday is, whether they acknowledge it or not, submitting to that authority.

The Irony of Sola Scriptura and Sunday Worship

The Fourth Commandment is unambiguous: "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). There is no verse in the entire Bible that transfers this commandment to Sunday, the first day of the week. Not one.

The texts sometimes cited in favor of Sunday — Acts 20:7, 1 Corinthians 16:2, Revelation 1:10 — do not command Sunday worship, do not call Sunday the Sabbath, and do not abrogate the seventh-day commandment. They are, at best, incidental references to first-day gatherings, not divine legislation.

The Catholic Church, to its credit, has been remarkably candid about this. Numerous Catholic catechisms and publications have openly stated that Sunday observance is a mark of the Church’s authority — and that Protestants who keep Sunday while claiming Sola Scriptura are living in a logical contradiction.

The Reformation’s Incomplete Work

The Protestant Reformers recovered many precious truths: justification by faith alone (Romans 5:1), the priesthood of all believers (1 Peter 2:9), and the supreme authority of Scripture. But they did not complete the Reformation. They carried Sunday worship with them out of Rome, and most of their spiritual descendants have never questioned it.

The prophet Isaiah foresaw this very situation: "To the law and to the testimony: if they speak not according to this word, it is because there is no light in them" (Isaiah 8:20). The test of every doctrine is not tradition, not church councils, not the weight of centuries — but the Word of God.

Jesus Himself warned: "In vain they do worship me, teaching for doctrines the commandments of men" (Matthew 15:9). And again: "If ye love me, keep my commandments" (John 14:15). The Sabbath is not a Jewish relic — it was instituted at Creation (Genesis 2:2–3), before there was a Jew on earth, and it was written by the finger of God in stone (Exodus 31:18).

The Only Consistent Position: Return to the Biblical Sabbath

If you believe the Bible is the Word of God, and if you believe that God’s law is still binding (Matthew 5:17–19; Romans 3:31), then there is only one logically and scripturally consistent position: keep the seventh-day Sabbath — from Friday sunset to Saturday sunset (Leviticus 23:32; Mark 1:32).

To continue observing Sunday while claiming Sola Scriptura is to concede the Archbishop’s point. It is to acknowledge, in practice if not in words, that the Church has authority over Scripture. The Reformation must be completed. The call of Revelation 14:7 — "Fear God, and give glory to him… and worship him that made heaven, and earth" — is a direct echo of the Sabbath commandment, pointing God’s people back to the Creator and His memorial day.

Key Points: Scripture vs. Tradition on the Sabbath

• The Fourth Commandment specifies the seventh day — Saturday — as the Sabbath (Exodus 20:8–10).
• No New Testament text commands Sunday worship or transfers the Sabbath to the first day.
• The change from Saturday to Sunday was made by the Roman Catholic Church, not by Scripture.
• Catholic sources openly acknowledge Sunday as a mark of Church authority over Protestant practice.
• Jesus kept the Sabbath (Luke 4:16) and declared Himself "Lord of the Sabbath" (Mark 2:28).
• The disciples rested on the Sabbath even after the crucifixion (Luke 23:56).
• The New Testament church in Acts worshipped on the Sabbath (Acts 13:14, 42–44; 16:13; 17:2; 18:4).
• Sola Scriptura, consistently applied, leads to seventh-day Sabbath observance.

The Reformation is not finished. The call to “come out of her, my people” (Revelation 18:4) is still going forth. Will you let Scripture — and Scripture alone — be your guide?