There is more to understand about Melchizedec than what is commonly taught in Christian circles.
First, Melchizedec is not a name, it is a title.
This man, who met Abraham, uniquely had two roles, he was "Priest of the God Most High" (Gen.14:18) and he was also the King of Salem (meaning 'peace') . Therefore, being both King and Priest - the combined titles make up the word we have mistakenly taken to be a given name, Melchizedec. Melchi is Hebrew for King, and Zedec or Zadok is Hebrew for Righteousness.
His Hebrew 'name' Melchizedec translated into English would simply be KingRighteousness.
(Therefore as a Priest of God, when he met Abraham, he came to bless him with the words of God given to him to deliver.)
What I want to do here is explain the connection between Melchizedec and Jesus, since the link between the two is stated in Heb 5:10 , "called by God as High Priest "ACCORDING TO THE ORDER OF MELCHIZEDEK,"
What is meant by 'order' ?
Order is defined in the dictionary as the arrangement or disposition of people or things in relation to each other according to a particular sequence, pattern, or method.
The 'order' we are examining is a called out succession of men, 'put in a row', meeting the requirements God Himself put forth.
What we readily understand is that under the leadership of Moses, we have God calling out one tribe of Israel -- the Levites, who would be in charge of the things concerning the worship and sacrifices and rituals of temple service.
From that tribe of Levites, God called out Aaron and his line of descendants to be the High Priests - standing in a place of service before God that only the High Priest could fill.
But what we miss is there is another line of priests that precedes the Mosaic 'law', a line of Zadok priests whose righteousness qualified them to serve as the High Priest of God.
The very first Zadok, (we are not told specifically) but we do have a hint, that Seth was 'an appointed seed'. (Gen. 4:25) and in his time people began to call on the name of the Lord.
What we are told is that Melchizedec was without question a Priest called of God in the line of Zadok or Righteous priests.
This line, including Melchizedec and traced through his 'seed', follows down into the tribe of Levites, and into the line of Aaron. Those in this line of Zadok priests were set apart from that of the other High Priests who needed themselves to be cleansed of their sin before entering the Holy of Holies to intercede for the sins of the people. (this is important as I will show)
It is important to note that the 'order' of the Zadok priests preceeds the law, because the final Zadok High Priest (Jesus) was not a High Priest under the law. Just as Melchizedec came to the father (Abraham) of those who walk by faith, (Rom. 4:16) so Jesus comes to the children of Abraham or those who, like him, walk by faith in Jesus, both Jew and Gentile.
While we could look at a thread of Zadoks traced through the Old Testament , I want to point out a verse in Ez. 48:11 that speaks clearly of the distinction of the Zadoks .. Verse 10 and 12 speak of the sanctuary of the Lord being placed in the middle of the 'most holy' district given to the descendants/sons of Zadok. Then verse 11 gives the reason why, "It shall be for the priests of the sons of Zadok, who are sanctified, who have kept My charge, who did not go astray when the children of Israel went astray , as the Levites went astray."
The Zakok Priests stayed faithful in their 'righteousness' before God, even when everyone around them was unfaithful. There was an unbroken line of Zadok priests ... ending with Jesus.
I showed in my last post how we know that Zacharias was the ligitamate High Priest rather than the impostor Caiaphas, but Zacharias was also a Zadok priest. How do we know ?
His righteousness is specifically noted, and also the righteousness of his wife Elizabeth, also an important detail. Why?
In II Chron. 27:1 we have a reference to the mother of a righteous king. It is noted that she was the daughter of Zadok . If the Hebrew word was used in our NT account, we would have it noted that Elizabeth was the daughter of the sons of Zadok. It is important that we have that fact. Mary, the mother of Jesus was related to Elizabeth, rather than John, so the 'seed of Zadok' (Ez. 46:19) was also passed to Mary, otherwise Jesus would not be in the seed line , or descendants of Zadok and He could not be linked to Melchizedec.
No priest could be annointed for service before the age of thirty. We read in Luke 3:23 at the time of his baptism by John, that Jesus begain His ministry at about thirty years of age.
Even at the age of twelve, Jesus was already astounding the leaders with His teaching in the temple - so His being a teacher had nothing to do with His age. It was important to note His age at His baptism because He was being anointed as the last and final Zakok High Priest.
It is also important that Jesus was of the seed of the Zadok High Priests, rather than just descended from Aaron because He did not have to be cleansed of His own sin before entering the Holy of Holies to make intercession for the sins of those He died for.
He was of the order of Melchizedec because He also holds a dual title, being not only a Righteous High Priest but also, like Melchizedec, a King of Peace, being of the tribe of Judah and a descendent of King David.