We will just have to disagree. If Sabbath keeping were to be an essential part of the New Covenant relationship with God it would have been mentioned in the discussion because it would have been an unfamiliar practice to the Gentiles.
Sabbath keeping was not even discussed because it was not a requirement for New Covenant believers. I believe that is why the duty to keep the Seventh day as Sabbath is not mentioned ONCE in the New Testament?
Thats my story and I'm sticking to it. Take care.
Actually the Sabbath would have been one of the MOST familiar of all Jewish practices to these Gentiles because most of Paul's Gentiles disciples became believers after hearing Paul speak in the synogogue, which would have been on the Sabbath. These folks were already keeping the Sabbath, that's why it's not really mentioned much in the NT (it is mentioned, especially in Acts and in recitations of Paul's travels)
As you read the NT you find a lot of controversy over circumcision. I can tell you unequivocally that if someone in Apostolic times had actally said anything to the effect of "Saturday/Sabbath is no longer the day of worshipping G-d, we'll worship on Sunday from now on", I believe, to paraphrase the Apoostle John, "I suppose that even the world itself could not contain the books that would be written," about such a controversy.