I have to tell you I recently have been profoundly studying this myself, and this is what I have come up with so far...any one that can refute this please provide proof from the bible only. Not your own opinion.
1. The 7th day Sabbath mentioned in Genesis and through Leviticus was a day of "rest" only. The Sabbath worship did not make its presence until Leviticus 23, in which the "mosaic law" was discussed and presented and the Sabbath worship was instituted.
2. All before that time of Leviticus 23 people were worshiping, and yet the "sabbath" was never mentioned as a "day of worship". We still understood the 7th day of the week to be a day of "rest". Exodus 20:8-11
3. Then throughout the rest of time the Jews as well as others followed the "mosaic laws" which included the seventh day worship, as well as the New Moon Feasts, Passover, ect. This of course included Jesus and the apostles.
4. Jesus is crucified, and therefore all the "Mosaic Law" is nailed to the cross....except of course for the 10 commandments which remain and of course are not part of the "mosaic law".
5. The 10 commandments make very clear what the Sabbath is intended for...there are no words left out, as we know God himself wrote the 10 commandments with his own finger.
The fourth commandment states: “Remember the Sabbath day by keeping it holy. 9 Six days you shall labor and do all your work, 10 but the seventh day is a sabbath to the LORD your God. On it you shall not do any work, neither you, nor your son or daughter, nor your male or female servant, nor your animals, nor any foreigner residing in your towns. 11 For in six days the LORD made the heavens and the earth, the sea, and all that is in them, but he rested on the seventh day. Therefore the LORD blessed the Sabbath day and made it holy."
Notice NOWHERE does it state to worship on the sabbath...HOWEVER...it does state to keep the Sabbath holy. So how do we do that? Lets hear what God has to say about that:
He said to them, “This is what the LORD commanded: ‘Tomorrow is to be a day of sabbath rest, a holy sabbath to the LORD. So bake what you want to bake and boil what you want to boil. Save whatever is left and keep it until morning.’