Here is the Sunday Law enacted by Emperor Constantine for which he is so well known and more on the transition from paganism.
March, 321 A.D.
On the venerable Day of the Sun let the magistrates and people residing in cities rest, and let all workshops be closed. In the country, however, persons engaged in agriculture may freely and lawfully continue their pursuits; because it often happens that another day is not so suitable for grain-sowing or for vine-planting; lest by neglecting the proper moment for such operations the bounty of heaven should be lost. (Given the 7th day of March, Crispus and Constantine being consuls each of them for the second time [A.D. 321].)
Source: Codex Justinianus, lib. 3, tit. 12, 3; trans. in Philip Schaff, History of the Christian Church, Vol. 3 (5th ed.; New York: Scribner, 1902), p. 380, note 1.
Transition of "Day of the Sun"
[p. 122] This legislation by Constantine probably bore no relation to Christianity; it appears, on the contrary, that the emperor, in his capacity of Pontifex Maximus, was only adding the day of the Sun, the worship of which was then firmly [p. 123] established in the Roman Empire, to the other ferial days of the sacred calendar.
[p. 270] What began, however, as a pagan ordinance, ended as a Christian regulation; and a long series of imperial decrees, during the fourth, fifth, and sixth centuries, enjoined with increasing stringency abstinence from labour on Sunday.
Source: Hutton Webster, Rest Days, pp. 122, 123, 270. Copyright 1916 by The Macmillan Company, New York.
"On March 7, 321, Roman Emperor Constantine I decreed that
dies Solis Invicti (‘sun-day,’ or
Day of Sol Invictus, Roman God of the Sun) would be the Roman day of rest throughout the Roman Empire...
Though
Sol Invictus (meaning ‘The unconquered Sun’) was indeed a pagan Roman God, and had been featured on Roman coins, Constantine coopted this pagan heritage along with the Judeo-Christian following of the 10 Commandments by granting a day to honor God and rest for man. As the Roman Empire gradually converted to Christianity, Sunday became the natural day for the Sabbath and rest since Romans were already accustomed to Sunday as their day off."
March 7, 321: How Sunday Became the Christian Day of Rest - History and Headlines
"The early Romans initially adopted the earlier Greek Hellenistic religion that incorporated the worship of many deities, including Apollo and Helios—the sun god, who was known to the Romans as Sol. As time passed, Sol eventually took on the combined attributes of Apollo, Helios and Mithra. The early Roman Emperors promoted the rising cult of Sol Invictus with the addition of numerous new temples, statues, rites and festivals created in Sol's name. Like earlier solar deities, Sol's tasks included steering the sun-chariot across the sky each day, a reminder that this cult was a blending of monotheism and earlier paganism.
By promoting the cult and the consolidation of divine power into Sol, Roman emperors were able to please the military and also enhance their own power by identifying Sol as the source of imperial legitimacy; in some cases the emperors were able to promote themselves as the personification of Solon earth.
Constantine in the early 4th century advanced the pagan cult of Sol Invictus to the height of its popularity. Among his efforts was the minting of this special coin dedicated to Sol. Constantine also built his famous Arch in Rome, inscribed with several references to Sol Invictus, and positioned it carefully to align with the colossal 100' bronze statue of Sol that adjoined the Coliseum at the time. The rising popularity Christianity in Rome's rural areas was a factor in Constantine’s later adoption of Christianity as the Empire's official religious—a transition arguably made easier by the preceding, well accepted ideas embodied in and popularized by the cult of Sol Invictus." ..
Biblical Artifacts Ancient Coins and Artifacts from the Holy Land
"Sol Invictus played a prominent role in the Mithraic mysteries and was portrayed as being equated with, allied with, or an epithet of Mithras, although the relationship between the public cults themselves is controversial. The New Testament scholar Helmut Koester, in his book,
Introduction to the New Testament, says “Although Mithras appeared to be the most oriental god among the new deities, and although his cult was essentially celebrated in exclusive mystery associations—the Mithras cult was a “mystery religion” in the strict sense of the word—this god was received by the Romans without resistance, and at the end of the 3d century CE, as Sol Invictus he became the official god of the Roman state.” ..
The Dying-and-Rising Gods: Sol Invictus
The early believers kept Saturday as the Sabbath until March 7, 321 CE when Constantine passed his law requiring believers to worship on Sunday, the day the pagans worshiped the sun-god,
Sol Invictus. Believers continued to keep Saturday as the Sabbath but gradually were swept aside as the day of the sun took root in the empire, and we see the start of serious oppression for the day of worship, and many believers began to be persecuted by the Roman Catholic Church for keeping the Sabbath.
Rome had been the center of many of the pagan festivals and cults, and it was held that Mithras was born on what we now call Christmas day, and his followers celebrated the spring equinox. The
Sol Invictus, associated with Mithras, was one the main pagan cult the church faced and rather than reject it let it come into the church with its sun worship. The Cybele cult also flourished in Rome on today's Vatican Hill. They held that Cybele's lover Attis, was born of a virgin, died and was reborn annually. This spring festival began as a day of blood on Black Friday, rising to a crescendo after three days, in rejoicing over the resurrection. There was violent conflict on Vatican Hill in the early days of Christianity between the Jesus worshipers and pagans who quarreled over whose God was the true, and whose the imitation. Christianity came to an accommodation with the pagan Spring festival and used it to bring in unconverted pagans.
History clearly shows how the Pagan worship of
Sol Invictus and festivals got into the early church and it was never sanctioned by scripture or given by Christ and the Apostles.
Transition from Pagan to Christian
'This legislation by Constantine probably bore no relation to Christianity; it appears, on the contrary, that the emperor, in his capacity of Pontifex Maximus, was only adding the day of the Sun, the worship of which was then firmly [p. 123] established in the Roman Empire, to the other ferial days of the sacred calendar…
[p. 270] What began, however, as a pagan ordinance, ended as a Christian regulation; and a long series of imperial decrees, during the fourth, fifth, and sixth centuries, enjoined with increasing stringency abstinence from labor on Sunday.' - Source: Hutton Webster, Rest Days, pp. 122, 123, 270. Copyright 1916 by The Macmillan Company, New York.
'The Church made a sacred day of Sunday largely because it was the weekly festival of the sun; for it was a definite Christian policy to take over the pagan festivals endeared to the people by tradition, and to give them a Christian significance.' Source: Arthur Weigall, The Paganism in Our Christianity, p. 145. Copyright 1928 by G. p. Putnams Sons, New York. ...
Sunday Worship
By the time of Emperor Constantine, the Christian religion received imperial sanction and the bishop of Rome became more than just another bishop, and brought in a system of worship from another origin than Christianity.
After the fall of Rome, the Bishop of Rome served as a source of authority and continuity from the old empire but Rome had also been the center of the pagan priests and their temples during the Roman Empire, and they did not go away. The Bishop of Rome, to bring in more converts brought what they were familiar with and allowed the traditional Roman mysteries and deities of solar monism such as Mithras and Sol Invictus and idol worship back into the church, along with its Pagan doctrines, graven images and ceremonies. It renamed the mother goddess and others that were worshiped and brought them into the church at Rome, then with its influence it spread into the other centers of Christianity. So next lets take a look at the Roman mysteries and the changes to the day of worship and how they were brought in.
Christians at Rome had been faithful as they were persecuted for many years but as they became accepted and persecution stop, other challenges faced them. Greek philosophy and Gnosticism had been picked up and in Rome the old beliefs and festivals were still followed by the Romans and many Christian and leaders didnt see a problem with it. The first issue began when early in the life of the Church, disputes arose as the bishop of Rome allowed the celebration of the Pasch or Passover to continue till the following Sunday so Christians could also celebrate Spring Equinox festival as they had done before.
Now the danger of allowing the Christians to join in pagan solstice celebrations was overlooked as the new pagan 'converts' joined the church and swelled the numbers under the bishop of Rome. So you had a introduction into the early church of what many were familiar with from the tradition of ancient Rome, not from scripture and it began to spread throughout the empire.
