Heb 7:28, Heb 5:6, Heb 1:8-12, Heb 5:8-9
The Levitical priests eventually die. But because Jesus is forever, He will serve as a priest forever to save us completely. (Heb 7:23-25, Heb 7:28, Heb 5:6)
Heb 7:23 And they truly were many priests, because they were not suffered to continue by reason of death: 24 But this man, because he continueth ever, hath an unchangeable priesthood. 25 Wherefore he is able also to save them to the uttermost that come unto God by him, seeing he ever liveth to make intercession for them.
Heb 7:28 For the law maketh men high priests which have infirmity; but the word of the oath, which was since the law, maketh the Son, who is consecrated for evermore.
Heb 5:6 As he saith also in another place, Thou art a priest for ever after the order of Melchisedec.
In obedience to the word of God, Jesus died on the cross to complete the work of the high priest, thereby saving all who believe in Jesus as the Christ. (Heb 5:8)
Heb 5:8 Though he were a Son, yet learned he obedience by the things which he suffered;