Gen 26:5 Because that Abraham obeyed my voice, and kept my charge, my commandments, my statutes, and my laws.
Exo 20:8 Remember the sabbath day, to keep it holy.
Gal 3:29 And if ye be Christ's, then are ye Abraham's seed, and heirs according to the promise.
Why is the Sabbath such a problem for you? The only reason to have a new Sabbath is if you wish to worship a new god.
The second reference is Mosaic law and the Israelites were under the Law, which Christians are not.
The sabbath "is not a problem for me" as as a Christian I worship on Sunday, the first day of the week, the Lord's Day. I also worship God on Monday and Tuesday and I also worship God on Wednesday. I also worship God on Thursday, on Friday and on Saturday. Where two or three are gathered together in His name is also worship and so sometimes I'm worshipping several times a day. Not being under the Law, I really don't think about it.
As for Sunday, the Lord's day, that is a public worship and more of a testimonial to our faith than worship. That's why unbelievers go to church-- to be seen. However, it is also an appearing before the Lord, and good to do.
I don't know how you jump from our posts here to the conclusion I want to worship "another god".
This is really getting tiring. Everyone with any sense about them realizes that there has been a change of the law from the old covenant to the new covenant. Unless you insist on sacrificing animals and taking you medical conditions to a Levite and following all the old covenant ceremonial laws without any changes, then suggesting that those of use who see a change of the sabbath from the last day of the week to the first are "worshipping a new god" is just plain silly.
Certain portions of the law were a "shadow" of the finished work of Christ (Heb. 10:1). You do not need to worship in the shadows when the "Light of the World" has made His appearance.
The fact of the matter is that the seventh day under the old covenant was a sabbath day. But Jesus Christ, being the Lord the Sabbath, had the prerogative to change the day of the sabbath from the last day to the first day.
Those of us you are Christian sabbatarians believe He did precisely that, by the examples of His resurrection on the first day, His pouring out of the Holy Spirit on the first day, and the example of Paul and others in the church who worshipped on the first day. {For old covenant sabbatarians, the painful fact remains that nowhere in the NT do we find the Jewish/gentile church worshipping on the last day sabbath of the Jews.)
So let's at least be honest and admit this has nothing to do with worshipping other gods, unless you really do intend to circumcise your children and get a rabbi's OK to cut your hair.