The Letter to the Hebrews begins by stressing the superiority of the “word spoken in the Son” over all previous revelations “spoken in the prophets.” This includes the Great Lawgiver himself, Moses, the greatest of the prophets, and it indicates the fundamental weaknesses of the Levitical priesthood and its sacrificial system. The previous words from the prophets were true but partial and preparatory. However, now, “upon the last of these days,” God has “spoken” with great finality in one who is His “Son.”
Since this word is complete, it is “better than” the partial revelations of the past. For the Son “achieved the purification of sins,” then he sat down at God’s right hand as the “appointed heir of all things.”
Logically, this means the word spoken “in the prophets,” especially the Levitical code with its priesthood and sacrifices, failed to achieve the “purification of sins” so desperately needed by the people of God.
After demonstrating Christ’s superiority over the angels, the Letter warns that if the previous incomplete word included “just recompense” for disobeying and disrespecting it, likewise, believers cannot escape a FAR WORSE PUNISHMENT if they ignore the superior word that God has “spoken in the Son” - (Hebrews 2:1-4).
The Letter demonstrates the superiority of this new and final word by contrasting his priesthood, covenant, and sacrifice to the Levitical priesthood, covenant, and repeated animal sacrifices performed in the ancient Tabernacle.
The fact that God promised a future priesthood “after the order of Melchizedek” demonstrated beyond doubt that the Levitical priesthood was incapable of achieving the “purification of sins.” That priestly order required multiple priests and animal sacrifices, yet it was received at Mount Sinai as part of the Torah. Therefore, the promised change in the priesthood means also a “CHANGE OF LAW”:
(Hebrews 7:11-12) – “If indeed, therefore, there had been perfecting through means of the Levitical priesthood, for the people thereon have had based a code of laws, what further need was there according to the order of Melchizedek for a different priest to be raised up, and not according to the order of Aaron? FOR SEEING THERE IS TO BE A CHANGE OF THE PRIESTHOOD, OF NECESSITY, OF LAW, ALSO, COMES A CHANGE.”
Due to human mortality, the Levitical priesthood was dependent on lineal descent and multiple generations of priests. Humanity's frailty was always the weakness of the system. Therefore, a FUNDAMENTAL CHANGE IN THE LAW WAS NECESSARY, or at least, a change in the regulations governing the priesthood and sacrifices.
THE NEW HIGH PRIEST
In contrast, the priesthood “after the order of Melchizedek” is perpetual since it is based on the ENDLESS RESURRECTED LIFE of the Son. He is, therefore, the “priest forever” who serves his people in the “real Tabernacle not made with hands” - (Hebrews 7:15-17).
Unlike the Levitical priests, the priest, singular, after the “order of Melchizedek” is installed by the declared word of Yahweh - (“Yahweh swore and will not regret: You are a priest everlastingly”); therefore, he holds the priesthood “un-transmissible.”
Moreover, he became the “guarantor of a better covenant” and saves “to the uttermost” everyone who approaches God through him because he “lives evermore to intercede in their behalf” - (Hebrews 7:19-25).
Under the old system, once each year, the high priest entered the “holy of holies” with blood from sacrificial animals TO STAND BRIEFLY in the Sanctuary where he applied the blood of animals to cleanse the sins of the nation committed in the preceding year.
In contrast, Jesus entered the “Real Sanctuary” ONCE-FOR-ALL with his own blood to atone for the sins of his people, then he “sat down on the right hand of the throne of the Majesty in the heavens” WHERE HE REMAINS TO THIS DAY.
The old priesthood and its animal sacrifices were “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).
Jesus is also the mediator of a better covenant legislated on better promises. If the “first covenant” had been faultless, there would have been no need for a second one. However, having found fault with it, the Lord announced the coming days when “I will conclude a new covenant” with His people - (Hebrews 8:6-7).
According to Hebrews, this new covenant is NOT “according to the covenant” made at Sinai. It is NOT a “renewed” or modified covenant, but something new, one that was necessary because the old legislation was incapable of “achieving the purification of sins” - (Hebrews 8:8-13).
By establishing the promised new covenant through his sacrificial death, Jesus has rendered the “first one obsolete.” Even now. it is in the process of disappearing, at least, from the perspective of the author of Hebrews.
The jurisdiction of the Levitical code over the conduct and beliefs of the people of God has been superseded by the “word of the Son.” Therefore, anyone who wishes to return to or remain under the old system chooses a system that is obsolete and incapable of cleansing the stain of sin from the believer’s “conscience.”