Where did "Christian" worship on the "day of the Sun", Sunday, originate?
Did it not originate per the Roman emperor Constantine's law of 321 AD, which united "Christian" and pagans in the observance of the "venerable day of the sun", and declared "Sunday" as the official day of rest on which markets were banned and public offices were closed. (blue laws)
How were those "dwelling the earth" "deceived"? (Revelation 13:14)
Was it not by the "beast with two horns like a lamb", that being the ruler Constantine, who instituted the Roman Catholic Church, along his two horns like a lamb, Christ like leaders, Peter, the "worthless" shepherd of Zechariah 11:17, and Paul, the staff "Favor" (Zechariah 11:10), who along with Judas Iscariot (Zechariah 11:12-13), would be "annihilated" in one "month"/generation. Their followers would be among the "many" of Matthew 7, who would follow the pied piper Paul (false prophet) (Matthew 7:15)(dressed in sheep's clothing) down the path to "destruction". Paul's false gospel of Grace (lawlessness) (Matthew 7:23) being the music followed to destruction.
Constantine's law of…321 [C.E] uniting Christians and pagans in the observance of the "venerable day of the sun" It is to be noted that this official solar worship, the final form of paganism in the empire…, was not the traditional Roman-Greek religion of Jupiter, Apollo, Venus, and the other Olympian deities. It was a product of the mingling Hellenistic-Oriental elements, exemplified in Aurelian's establishment of Eastern Sun worship at Rome as the official religion of the empire, and in his new temple enshrining Syrian statutes statues of Bel and the sun…. Thus at last Bel, the god of Babylon, came into the official imperial temple of Rome, the center of the imperial religion. It was this late Roman-Oriental worship of one supreme god, symbolized by the sun and absorbing lesser divinities as subordinates or manifestations of the universal deity, that competed with young Christianity. This was the Roman religion that went down in defeat but infiltrated and colored the victorious church with its own elements, some of which can be seen to this day. (Cramer 4)
On March 7, 321, Sunday was declared the official day of rest, on which markets were banned and public offices were closed,[ Constantine the Great and Christianity - Wikipedia