The letter to the Hebrews is built on a series of comparisons that demonstrate the supremacy of the “word spoken in” Christ over all past revelations “spoken in the prophets.” The former “words” were true but partial and preparatory. But now, “upon the last of these days,” God has “spoken” with great finality in one who is a “Son.”
The word provided in the Son is complete and supreme, “having achieved the purification of sins” that is so vital to His people. This he did, and thereby, he qualified to become the high priest who sits evermore at the right hand of God where he mediates life and forgiveness for his people.
The letter contrasts his priesthood and sacrifice with the priesthood and repeated animal sacrifices of the Levitical system. Moreover, Jesus applied the blood from his once-for-all sacrifice to the altar in the “real Tabernacle not made with hands.”
The fact that God promised another priesthood “after the order of Melchizedek” means the Aaronic priesthood could not achieve the “purification of sins.”
Under that (now) obsolete system, “the people received the law.” But the change in priesthood promised by Yahweh also means “a change of law” - (Psalms 110:4).
Due to human mortality and weakness, the Aaronic priesthood is dependent on lineal descent and multiple generations of priests. In contrast, the priesthood “after the order of Melchizedek” is perpetual since it is based on an endless resurrection life.
The “weakness” of human mortality inherent in the old system means there was a “disannulling” of the former commandment, which could “make nothing complete” - (Hebrews 7:11-17).
Unlike the Levitical priests, the high priest after the “order of Melchizedek” was installed by the declared word and oath of God, and it is held by one who was resurrected. Therefore, Jesus holds the priesthood “nontransferable” and unchangeable.
By his death and resurrection, he became the “guarantor of a better covenant,” and he is able “to save to the uttermost” all those who approach God through him. Indeed, he “lives evermore to intercede on their behalf” - (Hebrews 7:19-25).
In contrast to the earlier priests, Jesus “sat down on the right hand of the throne of the Majesty in the heavens” and became the minister of “the Real Tabernacle,” and not of a tent pitched by man.
On the earth, the old system constituted “glimpses and shadows of the heavenly realities,” just as Moses was told to make the earthly Tabernacle “according to the pattern he had seen in the mount” - (Hebrews 8:1-5).
Likewise, having “attained a more distinguished ministry, he also is the mediator of a better covenant legislated upon better promises.” If the “first covenant” had been faultless, there would have been no need for a second.
But having found fault with it, the Lord announced the coming days when “I will conclude a new covenant”:
“…Not according to the covenant which I made with their fathers in the day when I took them by their hand, to lead them forth out of the land of Egypt, because they abode not in my covenant, and I disregarded them, says the Lord. Because this is the covenant that I will make with the house of Israel after those days, says the Lord, giving my laws into their understanding, upon their hearts, also, will I inscribe them: and I will become their God, and they shall become my people; and in nowise shall they teach everyone his fellow-citizen and his brother, saying: Get to know the Lord! Because all shall know me, from the least to the greatest of them; because merciful will I be as to their iniquities, and of their sins, in nowise will I be mindful anymore. In saying, of a new sort, he has made obsolete the first; but the thing that is becoming obsolete and aged is near disappearing!” - (Hebrews 8:6-13).
The new covenant is NOT “according to the covenant” made at Sinai. It is not a “renewed” or enhanced piece of legislation based on the regulations of the Torah, but a new covenant made necessary since the old one was incapable of achieving the “purification of sins.”
And the new covenant empowers all citizens of the kingdom to know God and establishes them as His people. Unlike all previous efforts, the covenant established by the “Son” achieved the purification of sins (“I will become merciful to their unrighteousness and their sins will I remember no more”).
By establishing the new covenant, Jesus “made the first obsolete,” and that means the jurisdiction of the previous covenant is no longer in effect – it has been superseded by the new one.
Moreover, anyone who removes him or herself from the authority of our “Great High Priest” places himself back under an incomplete and obsolete system that can “never cleanse the conscience from sin.”