The New Day of Worship:
Pliny and other historical writers of the first century note the specific tradition of Christians to meet on the first day of the week – Sunday, corresponding to “The Lord’s Day”, that is, the day of the Resurrection.
Yet the the Christian “sect” emerged out from the disciplined religion of Old Covenant Judaism. One of the most core beliefs of the Jews was the Sabbath day (on the Saturday). This was one of their most cherished and distinctive beliefs. What would cause so many Jews to join this new movement and give up the Sabbath for the “Lord’s day”?