[DouglasKC]

It’s not only Sabbatarianism but the Holy Trinity as well. Your view would mean the Church went very wrong very early, in apostolic times - without historical proof of that view. Nor scriptural proof, but I concede that via sola scriptura one can have scripture say a wide variety of heresy. There is historical proof for that.

Let me begin to answer with a question so I know where you're approaching this question from.

Do you believe that the authors of scripture, both old and new testaments, understood the trinity doctrine exactly as you and other Christians today understand it?

[D-fendr]

While we encounter it also in the Old Testament as in let us make man in our own image, the Holy Trinity was fully revealed to the Apostles by Christ as seen in “Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit.”

I think it’s safe to summarize the history afterward as the Church rejecting what it is not as the need arose with the teachers of heresies.

[D-fendr]

As for Sabbatarianism, we see Christian worship on the first day in Paul’s writing. and the earliest known Christian history. and thereafter.