Heb 2:17, Heb 5:8-10, Heb 6:20, Heb 7:26, Heb 9:11-12 Jesus became the great high priest to atone for our sins. (Heb 4:14-16, Heb 2:17)
Heb 4:14 Seeing then that we have a great high priest, that is passed into the heavens, Jesus the Son of God, let us hold fast our profession. 15 For we have not an high priest which cannot be touched with the feeling of our infirmities; but was in all points tempted like as we are, yet without sin. 16 Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need.
Heb 2:17 Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people.
Jesus is not of the priestly tribe of Levi, but he is a high priest according to the order of Melchizedek. (Heb 5:8-10, Heb 6:20)
Heb 5:8 Though he were a Son, yet learned he obedience by the things which he suffered; 9 And being made perfect, he became the author of eternal salvation unto all them that obey him; 10 Called of God an high priest after the order of Melchisedec.
Heb 6:20 Whither the forerunner is for us entered, even Jesus, made an high priest for ever after the order of Melchisedec.
Because Jesus is eternal, He is the eternal High Priest. As our eternal High Priest, Jesus died once for all to atone for our sins, so we no longer have to offer sacrifices. (Heb 7:21-27, Heb 9:11-12)
Heb 7:21 (For those priests were made without an oath; but this with an oath by him that said unto him, The Lord sware and will not repent, Thou art a priest for ever after the order of Melchisedec:) 22 By so much was Jesus made a surety of a better testament. 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. 26 For such an high priest became us, who is holy, harmless, undefiled, separate from sinners, and made higher than the heavens; 27 Who needeth not daily, as those high priests, to offer up sacrifice, first for his own sins, and then for the people’s: for this he did once, when he offered up himself.
Heb 9:11 But Christ being come an high priest of good things to come, by a greater and more perfect tabernacle, not made with hands, that is to say, not of this building; 12 Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us.