"If ye fulfil the royal law according to the scripture, Thou shalt love thy neighbour as thyself, ye do well: For whosoever shall keep the whole law, and yet offend in one point, he is guilty of all. For he that said, Do not commit adultery, said also, Do not kill. Now if thou commit no adultery, yet if thou kill, thou art become a transgressor of the law." James 2
The law of God contains His commandments which fulfill His law. The commandments are points of law, not independent commands separate from the law.
And all the law is commandment of God: "That thou mightest fear the LORD thy God, to keep all his statutes and his commandments, which I command thee...But as for thee, stand thou here by me, and I will speak unto thee all the commandments, and the statutes, and the judgments, which thou shalt teach them...Ye shall observe to do therefore as the LORD your God hath commanded you."
The law is one law commanded by one commandment. It is a whole law without separating parts, and in the Old Covenant it is called the law of a carnal commandment. (Heb 7)
The law and commandant of God by Moses was called carnal, because it commanded physical obedience only. The change in law of God from that of Moses to that of Christ was of necessity due to the new birth with divine nature by the faith of Jesus. The Law of God by Christ is now of oath and in the Spirit, called the law of the Spirit.
The commandment now is to repent of dead works and to be changed from within by the Spirit, so that the commandment now is to the inner man first. No more just a carnal commandment against adultery, but the commandment against lust in the heart, which was never commanded in the law of Moses commanded by God in the mount and above the mercy seat.
Therefore, the change of the law of God by necessity from Moses to Christ is completely bound in the change for outward obedience only, carnally, of the flesh, to inward obedience of the heart and the Spirit, against which there is no law. So that he is a Jew that is circumcised inwardly, and he is not a Jew that is circumcised of the flesh only.
They who hold to the carnal commandment of Moses of old, judge not according to faith and spirit inwardly, but only according to the appearance of outward obedience to a law that is past. They have circumcised themselves with carnal hands of a carnal commandment, so that they have made themselves outward in obedience only, not inwardly by the Spirit.
And so, without any regard to confession of faith and sincerity of heart, if the Sabbath is not physically kept, then they are condemned as transgressors unworthy of fellowship in Christ. They thereby separate themselves from the body of Christ by carnal ordinance, even as they separate commandment from law of God, and have not the Spirit. (Jude)
Even as the Pharisees were in the Sabbath, and the Judaizers were in circumcision, so are these worshippers of the Sabbath: they are separatists, elitists, holier-than-thou lawgivers and judges. They have defined themselves by their Sabbath in their own religion, even as the Jews have defined themselves by circumcision in the Jews' religion.
The commandment of the Sabbath is their greatest commandment, for without the keeping of it carnally, they have no fellowship in faith. All the law hangs on it with themselves as keepers and proselytizers.