Is Saturday or Sunday the Sabbath?
God created the world in six days and rested on the seventh (Gen. 2:2). Likewise, God commanded his people to work six days and then rest on the seventh (Gen. 2:2; Exod. 20:8-11). For thousands of years, God’s people rested from their labors and worshiped their God on Saturday.
So why do Christians worship on Sunday?
The early church abruptly changed the day of worship to Sunday to commemorate the resurrection of Jesus from death on the “first day of the week.
As a faithful Jew, Jesus observed the Sabbath (not including the extraneous Sabbath rules made up by the religious leaders). But everything changed when he was crucified on a Friday and then rose from the dead on a Sunday.
In Jesus, the old covenant law was fulfilled, the new covenant arrived, and everything that was anticipatory and preparatory for the coming of Jesus was fulfilled in the resurrection of Jesus.
Spiritually speaking, the whole world changed, and now all things are in the process of becoming new through Jesus. A new day represents the new reality that was brought into being through the resurrection of Jesus.
To mark the monumental importance of this event, the early church broke from thousands of years of tradition and started worshiping on Sunday instead of Saturday.
At the time, however, Sunday was like our Monday. It was the day everyone returned to work after a day off.
Consequently, the early church would have likely had to gather for worship either in the morning or evening. This remained the case until Emperor Constantine instituted Sunday as an official day of rest in A.D. 321. But for the early church, Sunday was a day devoted primarily for worship, not rest.