What Did Rome Change?

The Filioque and the Sabbath

This page compares two disputes about doctrine, worship, and church authority: the Western addition of filioque to the Creed, and the development of Sunday observance alongside continuing Saturday liturgy and varied practices of rest. The histories are not identical, and the evidence does not establish that one caused the other. The comparison is narrower: in both disputes, Christians ask who may change a received form and what authority such a change requires.

What Happened to the Creed

The Creed received from Constantinople (381) says that the Holy Spirit proceeds from the Father. The Latin word filioque, meaning “and the Son,” appears in King Reccared’s profession at Toledo in 589. The first insertion into the Creed is less clearly documented. Pope Leo III later affirmed the doctrine while resisting the added wording. Rome began using the Creed with the clause at papal Mass in 1014.

The dispute concerns both theology and authority. Orthodox theology guards the Father as the Spirit’s single eternal source. Catholic theology teaches procession from Father and Son as one principle, with the Son receiving this eternally from the Father. The claim is about personal origin, not only the Son’s sending of the Spirit. The Council of Florence defended both the doctrine and the added wording in 1439. Catholics receive that council as ecumenical; Eastern Orthodox churches do not. Different Greek and Latin terms help explain the disagreement but do not, by themselves, resolve it.

A joint North American Orthodox-Catholic consultation traced that history and recommended that the Catholic Church use the original Greek text of 381 as the basis for translations intended for catechetical and liturgical use. Its agreed statement records serious convergence, but it is a bilateral consultation, not an ecumenical decree binding either communion.

What Happened to the Day

The Fourth Commandment names the seventh day as the Sabbath. Sunday worship also appears early in Christian history, and most Christians understand the Lord’s Day through Christ’s resurrection, apostolic practice, and the church’s authority rather than as a simple rewriting of Exodus 20. This book argues that those reasons do not amount to a New Testament command transferring the Sabbath’s sanctity to Sunday.

Constantine’s 321 law made Sunday a civil day of rest for many urban workers. Canon 29 of the regional Council of Laodicea later opposed resting on the Sabbath in a Judaizing manner and directed Christians to honor the Lord’s Day. Those facts show legal and ecclesial development. They do not, by themselves, prove a single coordinated Roman act that changed the day for every Christian.

The Comparison and Its Limit

The filioque history supplies a documented dispute over creed, theology, and authority. The Sabbath history supplies a different dispute over commandment, worship, and authority. This book sees an analogy between them: a received form remained in view while Western practice and its stated justification developed. That is an interpretive comparison, not evidence of shared causation.

The strongest objection to the comparison is that the Catholic Church does not regard either development as a rejection of apostolic faith. Catholic accounts defend doctrinal development and the church’s teaching authority; many Protestant accounts defend Sunday from the New Testament without appealing to Rome. The book’s narrower challenge remains: identify the text or authority that permits the change being defended.

Sources and Further Study