A Change in priesthood, and a change in the Law

Hebrews 7:1 Melchizedek was King of Salem and priest of the Most High God. He met Abraham returning from the defeat of the kings and blessed him. And Abraham gave him a tenth of every thing, First his [Melchizedek] name means, king of Righteousness, also king of Salem, which means king of peace. Without father, without mother, without genealogy, without beginning, and without end of life. Like the Lord Jesus Christ,  The Son of God, He remains a Priest forever. Now consider how great this man [Melchizedek] was, Unto whom the patriarch Abraham gave the tenth of the spoils.The Law requires that the descendants of Levi, who receive the office of the priesthood, have a commandment to take tithes of the people.according to the Law. that is of their brethren, though they come out of the loins of Abraham: But [Melchizedek] he whose descent is Not counted  from them received tithes of Abraham, and blessed him that had the promises. The less is blessed by the better.  In one case the tithes is Collected by men who died; but in the other case by him who is declared to be living. And as I may say so Levi also who received tithes, paid tithes to Abraham. When

Melchizedek met Abraham, Levi was in the body of his ancestor body. meaning he was not yet born.
If perfection could be obtained through the Levitical priesthood, For on the bases of the Law it was given, to the people. then, why? was there still need for another  priest to come, One in the Order of Melchizedek. And not in the order of Aaron, For when there is a change of priesthood, there must be a Change in the Law.  those of whom these things are said to belong to a different tribe, at the Alter,  For it is clear that our Lord descended from Judah, and in regards to that tribe, Moses said nothing, concerning priesthood. The Law makes nothing perfect, but the bringing in of a better hope did: By which we draw near to God. Yet it is for more evident that after the Similitude of Melchizedek there arises another priest who is made, not after the Law of carnal Commandments but after the power of  on endless life. For He [God] testifies, Thou art a Priest for ever after the Order of Melchizedek. [Speaking of the Lord Jesus Christ, again in Psalm 110:4, The Lord has sworn, and will not repent, Thou art a Priest forever after the order of Melchizedek. COLOSSIANS 3:1,

Melchizedek met Abraham when he was returning from the rescue of Lot his nephew, The priesthood   and law by which  perfection could not come, have been done away with, A Priest is risen, and a dispensation now set up, by which true believers may be made perfect. The law which made the Levitical priesthood were, frail, because each priest were priest only until death, and was not able to saved the souls of those who came to them. But the High Priest of our profession holds His office by the power of endless life in Himself; The Lord Jesus Christ, give eternal life to all who come to God by faith, through Him, [Jesus.] There were a lot of priest in the past, one after the other, each high priest serve until he die, then the next one take over,The Lord Jesus Christ, was made an High priest by an oath, [of God the Father,] that He [Jesus] will be a Priest forever after the Order of Melchizedek. Hebrews 5:10, called of God an High Priest after the order of Melchizedek.  Because of this oath, Jesus has become the guarantee, Of a better covenant. Because He lives to make Intercession for us. He is able to meet our needs. unlike the other High priest, our Lord does not need to offer Sacrifices, year after year. Leviticus 9:7, And Moses said unto Aaron, go unto the Alter, and offer thy sin offering, and thy burnt offering, and make an atonement for thyself, and for the people: