There is only one law of God (now the Law of Christ) because there is only one nature of God and that nature (Law) existed for eternity before the creation of the physical universe. The Law of God is spirit and His nature cannot be divided nor terminated. What that means is the law of God is the way He is.
Now God reveals His nature (His law) to man at various times through contracts (covenants). Each contract has different and similar terms but it is the only way God can relate to men… by men coming to terms through contract (covenant) with His nature.
The covenant God Almighty made with Abraham is the law of God (His nature) given through contract to Abraham. The old national covenant (not just the 10 commandments) is the law of God (His nature) given through contract to the nation of Israel. The new covenant is the law of Christ (His nature) given through contract to the children of God. The covenants (contracts) all have different and similar terms but it is the same eternal law of God (His nature) that came through different contracts (covenants).
Under the Law of Christ through the new contract we fulfill the law of God because by the indwelling of the Holy Spirit we can be transformed into His nature (fulfilling His law). We are not bound to the identical terms and conditions of the old national contract that were necessary (being without the Holy Spirit) to approximate His nature at best.
Thus the New Covenant is far superior to the Old Covenant because it requires an adjoining with the Holy Spirit to properly keep and it has many more commandments than the Old Covenant that are transmitted to the very recesses of the mind and soul by the Holy Spirit. Every teaching that proceeds out of the mouth of Christ is not a suggestion but it is a commandment.
Now those under the Old national contract/covenant could keep it without the Holy Spirit as long as they followed all the ordinances and periodic cleansings that were attached to the contract. Just observing the 10 commandments is not nearly enough. Those who teach 10 commandment keeping believe that Christ replaced the required cleansings and animal sacrifices of the old contract leaving the 10 commandments and some Sabbath keeping intact but that is not the case. The New Covenant is a new and different contract which when observed completely replaces the old contract and does not amend itself to the old contract. It’s not called the "Amended" or the “Revised” Covenant/contract but the “New” Covenant/contract.
Now the old covenant is a beautiful covenant. However it was created not for the individual but for the purpose of nationhood on this earth under God. It is a national contract/covenant. It was designed to serve as a constitution for a sovereign physical nation ruled directly under God with it’s own protected boarders and a real supernatural Army commanded by the Lord. The old national contract was not designed to be observed by individuals held captive within modern Egypt/Rome. This is why God didn’t give the old national contract to Enoch, Noah, Abraham, Isaac, or Jacob. With them He made covenants but they were between God and the individual. To properly keep the old national contract/covenant with all its Sabbaths, feasts, and ordinances etc… one must sever all physical and legal ties to their citizenry by birth, by vow or by forced servitude (a perpetually indentured population is what we have in place today).
This is what God had to do for the children of Israel before He gave them this magnificent national covenant through Moses: God had to sever all physical and legal ties to their Egyptian citizenry by birth, by vow or by forced servitude. And of course we all know what God had to do to accomplish that severing which culminated in the destruction of a military belonging to the most powerful nation on earth that laid legal claim to its enslaved population.
Today what old covenant keepers (Ten commandment Sabbath keepers etc..) have is not the old national contract but a make believe contract. It’s a make believe contract because it has been made up by one party who imagines (makes believe) that a second party has ratified it. In this case: all old covenant law promoters today do not observe the old covenant in its entirety because it’s a national contract that was designed for a sovereign nation not an individual person enslaved within modern Egypt/Rome.
So to keep the old national contract they have usurped God’s authority and revise the contract by selecting the parts that are practical for the individual to keep while enslaved within modern Egypt/Rome. Then they have to “make believe” that God ratified this revision. Therefore the contract is make believe - null and void.
Now there is nothing wrong with incorporating certain observances from this wonderful national contract into one's walk with God. But one need understand that this national contract was not designed for the individual with physical and legal ties to their current citizenry (Rome) by birth, vow or forced servitude. And the purpose of Christ’s sacrifice was not to sever those legal ties so that the individual could select certain observances contained in the national contract just up until the point of inconvenience or before violating any laws of their citizenry.
What this means is that people who decide to keep this national contract must understand that they can never keep it properly as it was originally intended because it was not intended for the individual under legal bondage to their citizenry but it was intended for an entire nation of people free from all legal ties and obligations to their citizenry by birth, by vow or by forced servitude.
Christ did not allow Himself to be slowly tortured to death so that individuals could fulfill the requirements of the old national contract while only observing certain ordinances that were convenient or in agreement with the authorities of their nation by birth. by vow or by forced servitude.
This is why we have a new contract: a better contract because it’s a spiritual contract… those under it worship God purely in spirit and truth. By spirit meaning our service to God is invisible and bears the visible fruits of the Spirit unlike the visible service under the old national covenant. And it’s done in truth from a pure and sincere heart. And this covenant, unlike the old national covenant, can be fully kept under Christ’s light yoke no matter what conditions the individual is under whether slave or free.
Now what did Christ mean when He said, "For truly I tell you, until heaven and earth disappear, not the smallest letter, not the least stroke of a pen, will by any means disappear from the Law until everything is accomplished"
This verse can only be properly understood when people understand the difference between God’s Law, which is eternal spirit, and a contract/covenant. First of all I'll repeat: God’s Law is spirit. God’s Law is His nature. They are one and the same which have always existed before the creation of heaven and earth.
Now notice Christ said: “disappear FROM the Law.” He said that it’s not the “Law” that will disappear when heaven and earth disappear but it’s the letter.... Meaning the least of the old contract (smallest letter...least stroke of a pen) through which the “Law” (which is spirit) was expressed through will disappear FROM the Law but the LAW will still remain because the Law is spirit. The Law was always here because it’s God’s nature… it’s the way He is but the old contract (the letter) was not always be here.
The old physical contract with the letter and stroke of ink from the pen will continue to exist as long as the temporal heaven and earth exist. But the temporal heaven and earth will be wiped out (disappear) when the permanent New Heaven and New Earth appear. And when the temporal heaven and earth disappear the physical letter and the physical stroke of pen will also disappear but the Law will still remain because the “Law” is spirit and has existed from eternity.
But since Christ a new and better spiritual contract has been created for the very few children of God who are drawn by the Father. It’s not like the old physical national contract made up of letter and pen and kept in a volt with the high priest who comes out once a year and reads it in the ears of the children of Israel. The children of God have received a new and better contract through which the Law (God’s nature) can be more appropriately expressed. The Law (God’s nature) can be more appropriately expressed because just like the Law… the contract through which the spiritual Law is expressed through is also spirit. It's not locked in a vault waiting to be taken out once a year by the high priest to be read into the physical ears of the people. The children of God receive God’s Law (His nature) by the Holy Spirit through a spiritual contract where now God’s Law (His nature) gets written directly on the hearts of God’s children by the Holy Spirit. You can not fully right down God's nature no matter how much pen and paper you have and the physical ear and eye will never be able to acquire God's nature from the letter.
But those who teach that keeping select portions of the old physical-national (make believe) contract is essential to salvation even with “the [largest] letter” and “the [greatest] stroke of a pen” have no hope of receiving God’s nature because they have set up a barrier (among many other barriers) between themselves and the Holy Spirit (God). The Holy Spirit can only operated through the new spiritual contract/covenant. Those who teach that their make believe contract is essential for salvation have unwittingly entombed themselves within the temporal creation ("heaven and earth") which has been slated for destruction (will "disappear").