'Perfection' in the Bible

"Can you discover the essence of God? Can you find out the perfection of the Almighty?

(Samek) All who passed by on the road clapped their hands to mock you. They sneered and shook their heads at Daughter Jerusalem. "Ha! Is this the city they called 'The perfection of beauty, the source of joy of the whole earth!'?"

"Son of man, sing a lament for the king of Tyre, and say to him, 'This is what the sovereign Lord says: "'You were the sealer of perfection, full of wisdom, and perfect in beauty.

So if perfection had in fact been possible through the Levitical priesthood -- for on that basis the people received the law -- what further need would there have been for another priest to arise, said to be in the order of Melchizedek and not in Aaron's order?