The ones commanded by the Catholic Church not to worship on Saturday kept the Sabbath day Holy. By resting on that day as commanded by the Lord.
CANON XXIX.
CHRISTIANS must not judaize by resting on the Sabbath, but must work on that day, rather honouring the Lord's Day; and, if they can, resting then as Christians. But if any shall be found to be judaizers, let them be anathema from Christ.
In the 4th century,
Socrates Scholasticus (
Church History, Book V) stated:
[21]
For although almost all churches throughout the world celebrate the sacred mysteries on the sabbath of every week, yet the Christians of Alexandria and at Rome, on account of some ancient tradition, have ceased to do this. The Egyptians in the neighborhood of Alexandria, and the inhabitants of Thebaïs, hold their religious assemblies on the sabbath, but do not participate in the mysteries in the manner usual among Christians in general: for after having eaten and satisfied themselves with food of all kinds, in the evening making their offerings they partake of the mysteries.
In the 5th century,
Sozomen (
Ecclesiastical History, Book VII), referencing Socrates Scholasticus, added to his description:
[22]
Assemblies are not held in all churches on the same time or manner. The people of Constantinople, and almost everywhere, assemble together on the Sabbath, as well as on the first day of the week, which custom is never observed at Rome or at Alexandria. There are several cities and villages in Egypt where, contrary to the usage established elsewhere, the people meet together on Sabbath evenings, and, although they have dined previously, partake of the mysteries.
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):
[16] "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."
[16][17] Section VII reemphasizes this:
[18]
Be not careless of yourselves, neither deprive your Saviour of His own members, neither divide His body nor disperse His members, neither prefer the occasions of this life to the word of God; but assemble yourselves together every day, morning and evening, singing psalms and praying in the Lord’s house: in the morning saying the sixty-second Psalm, and in the evening the hundred and fortieth, but principally on the Sabbath-day. And on the day of our Lord’s resurrection, which is the Lord’s day, meet more diligently, sending praise to God that made the universe by Jesus, and sent Him to us, and condescended to let Him suffer, and raised Him from the dead. Otherwise what apology will he make to God who does not assemble on that day to hear the saving word concerning the resurrection, on which we pray thrice standing in memory of Him who arose in three days, in which is performed the reading of the prophets, the preaching of the Gospel, the oblation of the sacrifice, the gift of the holy food?
[18]
Until the
Council of Laodicea, "the Sabbath had been kept in many Christian Churches."
[19] 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.
[20] 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?"
[21] Neverthless,
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.
[14]
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."
[14] Writing in the fourth century, the early
Church Father,
Eusebius, taught that for Christians, "the sabbath had been transferred to Sunday".
[22] 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."
[2] In "the fourth and fifth centuries theologians in the Eastern church were teaching the practical identity of the Jewish sabbath and the Christian Sunday."
[2] 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."
[23] The
Council of Elvira, in A.D. 300, declared that individuals who failed to
attend church for three Sundays in a row should be
excommunicated until they repented of their sin.
[23]
Ethiopian Orthodox icon depicting
St. George, the
Crucifixion, as well as the
Madonna and Child
However, the Church father
Justin Martyr taught specifically that Jewish Sabbath according to the
Decalogue does not apply in a binding fashion to Christians. These teachings, the starting point of
Christian liberty, solidified in the early Church as a fundamental principle behind its rejection of Hebrew Sabbath practices in its observances, calling its legalisms
Judaizing. In the late 4th century, the 29th canon of the Council of Laodicea finally declared that Christians must not rest on the Jewish Sabbath, but must work on that day and if possible rest on the
Lord's Day, and that any found to be Judaizers are
anathema from Christ.
[24] As such, in many parts of Christianity, both East and West, Judaizing influences diminished and almost disappeared, became effectually non-Sabbatarian
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Now I just got all that from a quick look at wikepedia and I'm sure if you really wanted to find the truth you would do some digging on your end to see that there have always been those who kept the truth Sabbath day. And you can surely find better information proving this to fact from better historical sources.
I leave it up to you to look. Study to show thyself approved, seek and ye shall find.
