NOTES for Heb 7:20-28
Continuing the discussion of Christ as High Priest, the author of the epistle draws attention to the key difference that distinguishes Him from every high priest of the Levitical priesthood. The matter concerns death, which weighs upon every fallen person. And the point here is not only that after the fall every person is mortal.
The point above all is that death defines the whole life of a fallen person. In our ordinary state we all live while dying, and we begin to die from the very moment of our conception, even before we come into the world. Death has become an inseparable part of our fallen life. Meanwhile, it is precisely death that prevents a person, and indeed the whole universe, from being sanctified completely.
It is no accident that Yahwism traditionally sets against holiness (not in the sense of righteousness, as we often use the word today, but in the sense of consecration) not even sin, but impurity, as that which destroys the fullness and integrity of creation, bringing death into it and preventing it from being sanctified, from becoming part of the Kingdom completely and in fullness.
Of course, sin also defiles, but it is only part of the evil in which the world lies, the part directly connected with a person's spiritual life and spiritual self-determination. To be sanctified in fullness oneself and to become a mediator in this process for others, one must be free from death, and therefore free from the evil in which the world lies, including human sinfulness. But by definition there could be no such high priest from among the Levites: there are no sinless people on earth, and no examples of the living Torah are known among the Levitical priesthood.
It was necessary to resort to special purifying sacrifices for the priests. These, of course, did not free them from sin, but they gave the priest the ability to act, so to speak, "over" his own sinful nature, not allowing it to show itself while the priest was carrying out his service. But this was a half measure: the priest himself remained the same, and as soon as he moved away from the altar and returned to ordinary life, sin again gained power over him. That is precisely why, after the purifying sacrifices, the Torah forbids priests to leave the courtyard of the Tabernacle (or, later, the Temple courtyard) until the end of the period of their service, which could last from one day to several weeks.
Throughout this time the priest had to live by the Tabernacle or by the Temple. In practice, however, this state of affairs meant that the priest remained a priest in the full sense of the word only for a certain time, while he was serving: it was then that God, through his service and with his participation, sanctified the people, while at all other times the priest was no different from anyone else. With Christ it is not so: He is High Priest always; His whole life is the process by which He sanctifies the Church as His body, for sin has no power over Him, and therefore death has no place in His life. Once He comes into contact with it, Jesus immediately conquers it through the resurrection. Such a High Priest can sanctify His people and the whole world in fullness, so that it may become part of the Kingdom, as God intended from the very beginning.