Through His Paschal Mystery, i.e., His death and resurrection, Jesus Christ fulfilled the “spiritual truth” of the Jewish sabbath. “[F]or Christians its ceremonial observance replaces that of the sabbath,” fulfilling “the moral command of the Old Covenant” (Catechism of the Catholic Church, nos. 2175-76). Jesus, who is Lord even over the Sabbath, taught the early Church to fulfill the Sabbath and commemorate His Mystery on the first day of the week, Sunday: “The Sabbath was made for man, not man for the Sabbath; so the Son of man is lord even over the Sabbath” (Mk. 2:27-28). This celebration is the Sacrifice of the Mass, also known as “the breaking of the bread” (cf. Acts 20:7, 2:42).
DISCUSSION: As noted in all four Gospels, Christ rose from the dead on the day after the Jewish Sabbath, the first day of the week, i.e., Sunday (Mt. 28:1, Mk. 16:2, Lk. 24:1, Jn. 20:1). “Because it is the ‘first day,’ the day of Christ’s Resurrection recalls the first creation. Because it is the ‘eighth day’ following the Sabbath, it symbolizes the new creation ushered in by Christ’s Resurrection. For Christians it has become the first of all days, the first of all feasts, the Lord’s Day” (Catechism, no. 2174).
The Jewish Sabbath was instituted by God to establish a regular day on which He, as Creator, was to be honored. Not only was the Sabbath instituted to honor God as creator, but it also served as a memorial of Israel’s liberation from bondage in Egypt (Ex 31:15-16). The Christian observance of Sunday as the Lord’s Day not only worships God as Creator, but honors Christ, the Son, in his passion, death, and resurrection. Through the Paschal Mystery, the “spiritual truth” of the Jewish Sabbath was fulfilled. Christ did more than save us from bondage to an earthly captor, he saved us from spiritual bondage, freeing us from our sin. Understanding this truth, the early Christian communities met together on Sundays after the Resurrection to share the Eucharist, thus honoring the sabbath: “On the first day of the week, when we were gathered together to break bread. . .” (Acts 20:7).
There is no more fitting worship and praise we can offer God the Father than by honoring and offering His only Son (Mt. 10:40) through the Sacrifice of the Mass. We cannot honor Jesus Christ if we do not follow His teachings, which He has commissioned His Church to pass on. (cf. Mt. 16:18-19, 1 Tim. 3:15, Jn. 20:21). To ignore the Apostles, who established the Lord’s Day through the power of Christ and his Holy Spirit, is to ignore Christ Himself (Lk. 10:16, Jn. 13:20). St. Ignatius (d. 110), Bishop of Antioch and student of the Apostle John, wrote, “Those who lived according to the old order of things have come to a new hope, no longer keeping the Sabbath, but the Lord’s Day, in which our life is blessed by Him and by His death” (Catechism, no. 2175).
Those who disagree with the practice of Sunday worship, as opposed to Saturday worship, claim that the Church changed God’s commandment and is thus participating in “idolatrous worship.” St. Paul wrote to the Romans (Rom. 7:6) and again, in his letter to the Hebrews, “The days will come, says the Lord, when I will establish a new covenant with the house of Israel and with the house of Judah; not like the covenant that I made with their fathers. . . . In speaking of a new covenant he treats the first as obsolete. And what is becoming obsolete and growing old is ready to vanish away” (Heb. 8:8-9, 13).
Christ came and established a new covenant with His people. Sunday worship is one outward sign of the fulfillment of the old covenant in the new. As. St. Justin Martyr, writing in the second-century, said, “We all gather on the day of the sun, for it is the first day [after the Jewish sabbath, but also the first day] when God, separating matter from darkness, made the world; and on this same day Jesus Christ our Savior rose from the dead” (Catechism, no. 2174).