How could Melchizedek be priest of God Most High
READ HEBREWS
FOR EVERY HIGH PRIEST is taken from among men and appointed their representative before God, to offer gifts and sacrifices for sins. He is able to bear patiently with the ignorant and erring, since he too is beset by weakness; 3and because of this he is bound to make sin-offerings for himself no less than for the people.
So it is with Christ; he did not confer upon himself the glory of becoming high priest: it was granted by God, who said to him, ‘Thou art my Son; today I have begotten thee’;
"Thou art a priest for ever, in the succession of Melchizedek.’ 7In the days of his earthly life he offered up prayers and petitions , Because of his humble submission his prayer was heard: 8son though he was, he learned obedience in the school of suffering, 9and, once perfected, became the source of eternal salvation for all who obey him, named by God high priest in the succession of Melchizedek.
MELCHIZEDEK, king of Salem, priest of God Most High, met Abraham returning from the rout of the kings and blessed him; and Abraham gave him a tithe of everything as his portion. His name, in the first place, means ‘king of righteousness’; next he is king of Salem, that is, ‘king of peace’. He has no father, no mother, no lineage; his years have no beginning, his life no end. He is like the Son of God: he remains a priest for all time.
Consider now how great he must be for Abraham the patriarch to give him a tithe of the finest of the spoil. The descendants of Levi who take the priestly office are commanded by the Law to tithe the people, . But Melchizedek, though he does not trace his descent from them, has tithed Abraham himself, and given his blessing to the man who received the promises; 7and beyond all dispute the lesser is always blessed by the greater. Again, in the one instance tithes are received by men who must die; but in the other, by one whom Scripture affirms to be alive. 9It might even be said that Levi, who receives tithes, has himself been tithed through Abraham; 10for he was still in his ancestor’s loins when Melchizedek met him.
Now if perfection had been attainable through the Levitical priesthood - what further need would there have been to speak of another priest arising, in the succession of Melchizedek, instead of the succession of Aaron? For a change of priesthood must mean a change of law. And the One here spoken of belongs to a different tribe, no member of which has ever had anything to do with the altar. 14For it is very evident that our Lord is sprung from Judah, a tribe to which Moses made no reference in speaking of priests.
15The argument becomes still clearer, if the new priest who arises is one like Melchizedek, 16owing his priesthood not to a system of earth-bound rules but to the power of a life that cannot be destroyed.
For here is the testimony: ‘Thou art a priest for ever, in the succession of Melchizedek.’ the Law brought nothing to perfection; and a better hope is introduced, through which we draw closer to God.