
A lot of folks ask me this, most often in genuine curiosity, and because the Hebrew Scripture leaves no doubt that the Sabbath was Saturday—the seventh day of the week. “And on the seventh day God rested,” we all read in Genesis; there’s just no qualm about that, after God made the first human beings on the sixth day, Friday.
Indeed, Jews and early Christians shared the biblical practice of the Saturday Sabbath (in fact the only Hebrew word for Saturday is Shabbat) in the early Christian period. This was under the supervision and inspiration of James (the brother of Jesus), Peter, and other disciples. According to a leading Canadian religious history compendium, the first Christians followed Mosaic traditions, including sacrifice in the Jerusalem Temple, and the Saturday Sabbath work restrictions.
Many other scriptural configurations retain the multiple of seven, including the sabbatical year of rest for farmland and soil, the 49th year of Jubilee for the manumission of slaves, and, again, the weekly respite and prayer gatherings on Saturday. In Israel today, Sunday remains the first day of the work week, the school week, and the resumption of bus and train operations that were suspended on Friday evenings. Of course, Christians native to the Holy Land may adjust to the secular Sunday in terms of banking and grocery shopping, but they wholeheartedly offer devotions in the historic churches of Jerusalem, Bethlehem, and Nazareth—with the full sanction and protection of the Israeli government, incidentally.
Why did Christianity eventually change the Sabbath to Sunday? In the first place, candidly, it had to—in order to create a distinction from Judaism, its parent religion—but foil nonetheless. But there’s also significant evidence and precedent that played to this important transformation and Jews shouldn’t smugly think that Christians chose Sunday simply because “Saturday was already taken.”
The Roman government intermittently persecuted the Jews at this time; it was safer for Christianity to be considered as a separate religion rather than as a sect of Judaism. In 321 CE, while he was a pagan sun-worshiper, the Emperor Constantine declared that Sunday was to be a day of rest throughout the Roman Empire. Ultimately, it became a given, theologically, politically, socially, even from the point of view of power and control, for Christianity to formally adopt Sunday as the Sabbath. The Church Council of Laodicea ordered that religious observances were to be conducted on Sunday, not Saturday. Sunday became the new Sabbath. They ruled: "Christians shall not Judaize and be idle on Saturday, but shall work on that day."
The Jewish community has never challenged the Christian Sabbath (not even being in a position to) and welcomes the postmodern respect—even affection—for Jewish customs that are so integral to most Church liturgies, some sixty years after the Holocaust. Islam, which came along in the fifth century, and selected Friday, will hopefully follow suit.