A Change of Priesthood

[Heb 7:11-14, 16-17 KJV] 11 If therefore perfection were by the Levitical priesthood, (for under it the people received the law,) what further need [was there] that another priest should rise after the order of Melchisedec, and not be called after the order of Aaron? 12 For the priesthood being changed, there is made of necessity a change also of the law. 13 For he of whom these things are spoken pertaineth to another tribe, of which no man gave attendance at the altar. 14 For [it is] evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood. … 16 Who is made, not after the law of a carnal commandment, but after the power of an endless life. 17 For he testifieth, Thou [art] a priest for ever after the order of Melchisedec.