Hebrews 7:11-22 New Revised Standard Version (NRSV)
Another Priest, Like Melchizedek
11 Now if perfection had been attainable through the levitical priesthood—for the people received the law under this priesthood—what further need would there have been to speak of another priest arising according to the order of Melchizedek, rather than one according to the order of Aaron? 12 For when there is a change in the priesthood, there is necessarily a change in the law as well. 13 Now the one of whom these things are spoken belonged to another tribe, from which no one has ever served at the altar. 14 For it is evident that our Lord was descended from Judah, and in connection with that tribe Moses said nothing about priests.
15 It is even more obvious when another priest arises, resembling Melchizedek, 16 one who has become a priest, not through a legal requirement concerning physical descent, but through the power of an indestructible life. 17 For it is attested of him,
“You are a priest forever,
18 There is, on the one hand, the abrogation of an earlier commandment because it was weak and ineffectual 19 (for the law made nothing perfect); there is, on the other hand, the introduction of a better hope, through which we approach God.
20 This was confirmed with an oath; for others who became priests took their office without an oath, 21 but this one became a priest with an oath, because of the one who said to him,
“The Lord has sworn
22 accordingly Jesus has also become the guarantee of a better covenant.