Not by a long shot. This question has been addressed by Catholic Answers Magazine before, but perhaps I, as a convert to the Catholic Church from Seventh-day Adventism, can offer a fresh perspective on the matter.
While it is true that there is no New Testament record of a voice from the heavens instructing the infant Church, “Thou shalt change the day of thy worship and rest from Saturday to Sunday,” Adventists are mistaken in their belief that there is no New Testament evidence that supports such a change by the Catholic Church. Quite apart from the biblical proof of the apostolic Church’s authority to teach in God’s name (Mt 16:18–19, 18:17–18, Lk 10:16) and of God’s guarantee that this teaching would never fall into error (Mt 28:19–20, Lk 22:32, Jn 16:13), there is an impressive amount of evidence from Scripture that Christ and the apostles changed their day of corporate worship from Saturday to Sunday.
The Old Testament Sabbath commandment contains two elements. The primary element, and the one that binds Christians as it does Jews, is the moral obligation to set aside adequate time for the purpose of divine worship. This could never be abrogated, as it is rooted in the natural law.
The secondary element was ceremonial and therefore could be abolished—and was abolished by Jesus’ death on the cross (Col 2:12–17). This secondary, ceremonial element was that the particular day chosen to meet the moral obligation of the law was Saturday, so that the Jews would remember and memorialize the creation of the earth.
Jesus, during his earthly ministry, began to prepare the way for changing Sabbath worship from “the letter of the law” to “the spirit of the law.” Remember that one of his greatest arguments with the Pharisees concerned Sabbath worship. He constantly rebuked them for placing the rigid observance of mere details above the spirit of setting aside a day to rest from unnecessary servile work and to worship God. By this Jesus made it clear that the Sabbath may be changed to meet the needs of man. By effecting these changes as “the Son of Man,” Jesus used his human authority to show us that he is “Lord even of the Sabbath” (Mk 2:28).
As Frs. Rumble and Carty point out in Radio Replies, special honor is shown to Sunday throughout the New Testament. Christ rose from the dead on Sunday, and he first appeared to his disciples that Easter Sunday evening (Jn 20:19). One week later—and from the context we can see that this meant the following Sunday—Jesus appeared to them again when Thomas was present (John 20:26). Luke records that Sunday was observed by the Christian community from the very beginning: “On the first day of the week when we gathered to break bread” (Acts 20:7). To “break bread” refers to the celebration of the Eucharist (Mt 26:26, Mk 14:22). Paul ordered the Corinthians to gather their offertory collections on Sunday (1 Cor 16:2); that set the scriptural precedent we follow today of gathering our offerings on Sunday during Mass. John records in Rev. 1:10 that he was granted a vision of heaven’s own worship while he was at worship (“caught up in spirit”) on “the Lord’s day.” John’s disciple Ignatius of Antioch tells us in his Letter to the Magnesians that “the Lord’s day” is not the ancient Sabbath; therefore, “the Lord’s day” must refer to Sunday. (See This Rock, September 1994, “The Fathers Know Best.”)
Put this question to your Seventh-day Adventist friends: Jesus, being God, knew whether or not his Church would apostatize by changing the Sabbath from Saturday to Sunday. If Adventists are correct that Christians are still obliged to keep Saturday as their day of corporate worship, isn’t it strange that Jesus underscored exactly the opposite by appearing to his disciples after his Resurrection nearly exclusively on Sunday?