Constantine was the first ruler to enacted Sunday worship as law for one purpose: to unite the Roman world.
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 from Pagan to Christian[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.
Yes, the title Pontifex Maximus is pagan, derived from the Sun worshiping Roman Empire, and the source of the papal title of Pontiff.
Pope Sylvester first among the Romans ordered that the names of the days [of the week], which they previously called after the name of their gods, that is, [the day] of the Sun, [the day] of the Moon, [the day] of Mars, [the day] of Mercury, [the day] of Jupiter, [the day] of Venus, [the day] of Saturn, they should call
feriae thereafter, that is the first
feria, the second
feria, the third
feria, the fourth
feria, the fifth
feria, the sixth
feria, because that in the beginning of Genesis it is written that God said concerning each day: on the first, "Let there be light:; on the second, "Let there be a firmament"; on the third, "Let the earth bring forth verdure"; etc. But he [Sylvester] ordered [them] to call the Sabbath by the ancient term of the law, [to call] the first
feria the "Lord's day," because on it the Lord rose [from the dead], Moreover, the same pope decreed that the rest of the Sabbath should be transferred rather to the Lord's day [Sunday], in order that on that day we should rest from worldly works for the praise of God.
Note particularly, he says that "the same pope [Sylvester I] decreed that the rest of the Sabbath should be transferred rather to the Lord's day [Sunday]."[SUP]8[/SUP] According to this statement, he was the first bishop to introduce the idea that the divinely appointed rest of the Sabbath day should be transferred to the first day of the week. This is significant, especially in view of the fact that it was during Sylvester's pontificate that the emperor of Rome [Constantine] issued the first civil laws compelling men to rest from secular labor on Sunday, and that Eusebius, bishop of Caesarea, was the first theologian on record to present arguments, allegedly from the Scriptures, that Christ did transfer the rest of the Sabbath day to Sunday.
[SUP]6[/SUP] Rabanus Maurus, Liber de Computo (A book Concerning Computation), Chap. XXVII ("Concerning Festivals"), as translated by the writer from the Latin text in Migne's Patrologia Latina, Vol. CVII, col. 682.
Sylvester the pope first among the Romans ordered that the names of the days, which before they called according to the names of their own gods, that is (the day) of the sun, of the moon, of Mars, of Mercury, of Venus, of Saturn, they should call
feria (day of celebration), that is, first feria, second feria, third feria, fourth feria, fifth feria, sixth feria, because in the beginning of Genesis it is written that God had said for each day: first, "Let there be light"; second, "Let there be the firmament"; third, "Let the earth produce living plants", etc. But the Sabbath he commanded they call by the ancient name of the law, and the first feria the Lord’s day, because the Lord rose on that day. Moreover the same pope ordered that the rest (
otium) of the Sabbath would better be transferred to the Lord’s day, so that we should leave that day free of worldly works in order to praise God.
Daniel 7:25
He shall speak words against the Most High, and shall wear out the saints of the Most High, and shall think to change the times and the law; and they shall be given into his hand for a time, times, and half a time.