Hebrews 7:15-22

And this becomes even more evident if another priest arises in the likeness of Melchizedek, [Ps 110:4] who has become a priest, not on the basis of a physical and legal requirement in the Law [concerning his ancestry as a descendant of Levi], but on the basis of the power of an indestructible and endless life. For it is attested [by God] of Him, “YOU (Christ) ARE A PRIEST FOREVER ACCORDING TO THE ORDER OF MELCHIZEDEK.” [Ps 110:4] For, on the one hand, a former commandment is cancelled because of its weakness and uselessness [because of its inability to justify the sinner before God] (for the Law never made anything perfect); while on the other hand a better hope is introduced through which we now continually draw near to God. And indeed it was not without the taking of an oath [that Christ was made priest] (for those Levites who formerly became priests [received their office] without [its being confirmed by the taking of] an oath, but this One [was designated] with an oath through the One who said to Him, “THE LORD HAS SWORN AND WILL NOT CHANGE HIS MIND or REGRET IT, ‘YOU (Christ) ARE A PRIEST FOREVER’ ”). [Ps 110:4] And so [because of the oath’s greater strength and force] Jesus has become the certain guarantee of a better covenant [a more excellent and more advantageous agreement; one that will never be replaced or annulled].