It is true that the early Church changed the day of worship from Saturday to Sunday. This in no way violates the teachings of Scripture. Christians live under the New Covenant and not the Old. The Church in its God given authority (Matthew 16:15-19), made the change in honor of the day that Jesus rose from the dead. Scripture records the early Church meeting on the first day (Sunday).
For instance, in Acts 20:7 we read the following: "On the first day of the week, when we were gathered together to break bread, Paul talked with them. . ." The term "to break bread" refers to the Eucharistic celebration which has been the center of Christian worship for the last two thousand years. Money was collected for the needs of the Church on Sunday.
The Church's Scriptures that support Sunday worship:
Peter as head of the Catholic Church has the authority to change the Sabbath for the Church
17 Jesus answered and said to him, "Blessed are you, Simon Bar-Jonah, for flesh and blood has not revealed this to you, but My Father who is in Heaven. 18 And I also say to you that you are Peter, and on this rock I will build My church, and the gates of Hades shall not prevail against it. 19 And I will give you the keys of the kingdom of Heaven, and whatever you bind on earth will be bound in Heaven, and whatever you loose on earth will be loosed in Heaven."
Matthew 16:13-19
Paul encourages the faithful to set aside contributions of all types to support the Church
2 On the first day of every week, each of you is to put something aside and store it up, as he may prosper, so that contributions need not be made when I come.
1 Corinthians 16:2
Paul testifies Mass was being held every Sunday.
7 On the first day of the week, when we were gathered together to break bread, Paul talked with them, intending to depart [the next day]; and he prolonged his speech until midnight.
Acts 20:7
