Why do we go on Sunday versus another day of the week?
October 11, 2020, 12:00 PM
In most places, Mass is available to Catholics every day of the week but is mandated on Sunday, which is why most Catholics only go to Mass on that day.

God commanded His people to set aside the Sabbath for rest and prayer (see the third commandment). This is modeled on God’s own “rest” following the six days of Creation. Genesis tells us that on the seventh day, after God had created everything, He “rested” (see Gn 2:1-3).

The people of God before Christ came, and Jews to this day, observe the Sabbath rest on Saturday, the seventh and final day of the week. Christians have always observed the third commandment by keeping Sunday, rather than Saturday, holy. So you might ask, why do we worship on Sunday? Sunday, which is regarded as the first day of the week, is the day that God began His work of creation. Jesus rose from the dead on a Sunday. Therefore, Christians have always regarded it as the first day of the “new creation” – inaugurated by the resurrection and the new holy day.

Sunday is also figuratively referred to as the “eighth day” – the day that follows the completion of the old creation (which Genesis describes as occurring in seven days) and inaugurates a new (supernatural) creation that awaits us just beyond the seven-day cycle of time – the “day” of eternity. It is because of this that many baptismal fonts are eight sided. At that font we enter into this new creation. As St. Paul puts it, “If anyone is in Christ he is a new creation. The old is passed away; now all is new!” (2 Cor 5:17).

Sunday worship is not a discontinuation of the Sabbath observed before Christ on Saturday, but rather, is one of many ways in which the Old Covenant (i.e., Testament) has been fulfilled and completed in Christ.