“During this indefinite time a considerable amount of a sort of theokrasia seems to have gone on between the Christian cult and the almost equally popular and widely diffused Mithraic cult, and the cult of Serapis-Isis-Horus. From the former it would seem the Christians adopted Sunday as their chief day of worship in- stead of the Jewish Sabbath.” H. G. WELLS, “The Outline of History” (New and Revised), page 543.
“The first who ever used it [the Sabbath to denote the Lord’s day (the first that I have met with in all this search) is one Petrus Alfonsus-he lived about the time that Repurtus did (which was the beginning of the twelfth century)-who calls the Lord’s day by the name of Christian Sabbath.” PETER HEYLYN, “History of the Sabbath,” Part 2, Chap. 2, Sec. 12.
“Bear in mind that the substitution [of the first for the seventh day] was not a coerced happening; it could not be a sudden, but only a very slow development, probably never anticipated, never even designed or put into shape by those chiefly interested, but creeping almost unconsciously into being.” WILLIAM B. DANA, “A Day of Rest and Worship,” page 174.
The first direct reference to Sunday as a day of rest from physical toil we find in Tertullian, in about A.D. 200 in his Liber de Oratione, chapter 23. “We, however ( just as we have received ), only on the day of the Lord’s resurrection ought to guard not only against kneeling, but every posture and office of solicitude; deferring even our businesses lest we give any place to the devil.” TERTULLIAN, “Ante-Nicene Fathers,” Vol. 111, page 689.
“The early Christians had at first adopted the Jewish seven- day week with its numbered week days, but by the close of the third century A.D. this began to give way to the planetary week; and in the fourth and fifth centuries the pagan designations became generally accepted in the western half of Christendom. The use of the planetary names by Christians attests the growing influence of astrological speculations introduced by converts from paganism. … During these same centuries the spread of Oriental solar worships, especially that of Mithra (Persian sun worship) in the Roman world, had already led to the substitution by pagans of dies Solis for dies Saturni, as the first day of the planetary week…. Thus gradually a pagan institution was ingrafted on Christianity.” HUTTON WEBSTER, Ph.D., Rest Days, pages 220, 221.
Eusebius, fourth-century bishop and friend of the wicked Emperor Constantine, whose Sunday law is the first on record, flatly says: “All things, whatsoever that it was duty to do on the Sabbath, these we have transferred to the Lord’s day [as they had begun to call Sunday].” –“Commentary on the Psalms.”
“Opposition to Judaism introduced the particular festival of Sunday very early, indeed, into the place of the Sabbath…. The festival of Sunday, like all other festivals, was always only a human ordinance, and it was far from the intentions of the apostles to establish a divine command in this respect, far from them, and from the early apostolic church, to transfer the laws of the Sabbath to Sunday. Perhaps, at the end of the second century a false application of this kind had begun to take place; for men appear by that time to have considered laboring on Sunday as a sin.” AUGUSTUS NEANDER, General history of the Christian Religion and Church” (Rose’s translation), Vol. 1, page 186.