The institution of the seventh-day (Saturday) Sabbath as a weekly day of rest and worship goes all the way back to creation week in Genesis 2:1-3. God set the example for humankind by resting on that specific day. Indeed the Creator "blessed the seventh day and sanctified it." The word sanctify means "to set apart for a holy use and purpose."
When God led Israel out of Egyptian captivity, He again instructed them about the need to observe the Sabbath day (Exodus 16:23-30). Later God incorporated His instruction to keep the Sabbath day holy as one of the Ten Commandments (Exodus 20:8-11). Kept from Friday sunset to Saturday sunset, observant Jews still honor this same day as God's Sabbath.
During Jesus' earthly ministry He set an example of Sabbath keeping (Luke 4:16). And after Christ's death, resurrection and ascension to His Father, the early first-century Church continued to observe the seventh-day Sabbath (Acts 13:14, Acts 13:42, Acts 13:44; Acts 16:13; Acts 17:2; Acts 18:4).
In the centuries that followed, however, a satanic apostasy gripped the church and only a relative few remained faithful to apostolic teaching and doctrine (please see the chapter on "The Rise of Counterfeit Christianity" in our free booklet The Church Jesus Built).
The seventh-day Sabbath was one of the first doctrines that fell under attack, along with many of Christ's other teachings. Those who propagated these false doctrines began to observe the first day of the week, Sunday (the day commonly used to honor the sun god in the Roman Empire), as the official day of rest.
That practice soon became almost universal among professing Christians and remains so today. But scattered groups of believers have continued to observe God's true Sabbath through the centuries. To learn more, please read our free Bible study aid booklet Sunset to Sunset: God's Sabbath Rest.