You wrote:
“Historically, the change from Sabbath to Sunday has been attributed to the ecclesiastical authority of the Roman Catholic church rather than to Biblical or apostolic precepts.”
So what? Neither the first day of the week nor the Church is pagan in origin so you still have utterly failed to provide a single scrap of evidence for your claim.
ecclesiastical authority of the Roman Catholic church, not the bible or the apostles
No Christianity is not pagan but many of the practices of the RCC were take from the pagan religions of their day.