Before the 2nd century, there is no evidence that Christians held weekly meetings for worship on Sunday, but the evidence suggests that for half of this century, some Christians were voluntarily observing Sunday as a day of worship but not to rest. From the second century to the fifth, while on Sunday continued acquiring influence, the Christians continued to observe Saturday almost in all parts of the Roman Empire. The historian of the fifth century Socrates wrote: almost all churches throughout the world celebrate the sacred mysteries on the Saturday of each week, and however Christians of Alexandria and Rome, according to some ancient tradition, have ceased to do so. In the fourth and fifth centuries, many Christians worship both Saturday and Sunday. Sozomen, another historian of the century wrote: Constantinople, and almost everywhere, people gather on Saturday, as well as the first day of the week; This habit is never observed in Rome or Alexandria. These references show the leading role that fit you to Rome in the abandonment of the observance of the Sabbath. Popularity and influence which conferred you to Sunday worship to the Sun of the pagan Romans, undoubtedly contributed to his growing acceptance as a day of worship.
The worship of the Sun played an important role throughout the ancient world. The 4th century was witness of the introduction of the Sunday laws. First Sunday civilian laws were enacted, and were then appearing of a religious nature. Emperor Constantine issued the first Sunday law civil March 7 year 321D.C. in view of the popularity enjoyed by the Sunday among the pagans who worshipped the Sun, and the esteem in which many Christians did, Constantine was expected, doing a holiday Sunday, he could make sure the support of both groups for his Government. The Sunday law of Constantine reflected his own past as a Sun worshiper.