When the new testament lists sins, Sabbath breaking is conspicuously absent;
In Mark 7:21-22 13 sins are listed. Jesus did not mention breaking the Sabbath.
In Romans 1:29-32 20 sins are listed and not one of them is Sabbath breaking.
In Galatians 5:19-21 a list of 15 sins are given, not one of them is Sabbath breaking.
In 2 Timothy 3:1-4 there's a list of 18 sins, but not once is Sabbath breaking mentioned.
Don't you find it peculiar that nowhere in the New Testament is it taught that the fourth commandment must be observed?
Acts 15 prescribes basic Jewish practices for Gentiles to follow with the injunction that they will learn Moses in the synogogues on the Sabbath and learn the rest there? Yet now, most Christian churches only teach Torah as bed time stories?
Paul over and over again lauded and upheld Torah, yet Christians trample it under foot and then have the nerve to say that they are "free" to do so?
Romans 2:13 "(For not the hearers of the law are just before God, but the doers of the law shall be justified)."
Romans 3:31 "Do we then make void the law through faith? God forbid: yea, we establish the law."
Romans 7:12 "Wherefore the law is holy, and the commandment holy, and just, and good."
Romans 7:14 "For we know that the law is spiritual: but I am carnal, sold under sin."
Romans 7:22 "For I delight in the law of God after the inward man."
The very idea that you think that the NT is a trump card over the OT rather than an elaboration on it shows the root of your error. If you think those NT lists of sins are exhaustive, you make James and the Acts 15 counsel to be liars because they believed that it would be greatly beneficial for the new beleivers to learn Torah.
No - the 4th Commandment was around long before the others. That's why is says, remember the Sabbath. It was not necessary to repeat the sin of Sabbath breaking - no one questioned it.