Constantine.......................
You are correct. Constantine brought Sunday keeping into the church. It is amazing what Rome did too. Handing a secular power to a spiritual power. Unprecedented. And she is still there today.....a sovereign spiritual nation. Both state and religious and her influence once again growing world wide. And Sunday is being exalted in the name of climate change.
Sunday will unite her with her daughters who also accept her day and accept her authority. Revelation is about worship. Worship the beast or worship the creator......the Sabbath is a memorial to creation. And the dragon is wroth this those who keep the commandments of God. John sees the 10 commandments in heaven ....the tabernacle of the testimony.
And nobody changes that....not one jot or tittle. Jesus is Lord of the Sabbath. I’ll follow his example and his law. No thanks to Rome.
Constantine??? Not really - Christians had been celebrating Christ’s victory on the first day of the week for over 300 years - he just gave Christians the day off to celebrate it.
By the way - - the 10 commandments were fulfilled (completed) in Christ, thus their obedience (works) are no longer a condition for salvation. Faith in Jesus, however, is.