Moses pictured a certain man in this way,
“Then Melchizedek king of Salem brought out bread and wine; he was the priest of God Most High” (Genesis 14.18).
Those familiar with the priesthood and royalty of Israel know that a man could not be priest and king simultaneously, in fact, priests from the tribe of Levi could not be kings, and kings from the tribe of Judah could not be priests, because the Law of Moses only authorized priests from Levi, and the kings were to be sons of David, who was of the tribe of Judah.
Later when the Holy Spirit had David write Psalm 110, we discover that this Melchizedek served as a shadow or type of the Messiah,
“The LORD said to my Lord,
‘Sit at My right hand,
Till I make Your enemies Your footstool.'”
In the New Testament, the Bible makes this presentation of Melchizedek, and begins to lay the foundation for declaring that the priesthood of Jesus the Messiah is based on the priesthood of Melchizedek rather than that of Aaron,
“For this Melchizedek, king of Salem, priest of the Most High God, who met Abraham returning from the slaughter of the kings and blessed him, to whom also Abraham gave a tenth part of all, first being translated ‘king of righteousness,’ and then also king of Salem, meaning ‘king of peace,’ without father, without mother, without genealogy, having neither beginning of days nor end of life, but made like the Son of God, remains a priest continually” (Hebrews 7.1–3).
Later in the chapter the writer quotes Psalm 110 and applies it to Jesus, but we will withhold further comment on Psalm 110 in the New Testament, until we reach Psalm 110 in this listing of the Messianic Prophecies of the Old Testament.
We need to add that Jesus would not violate the Law of Moses. How then could He be a priest since He was from the tribe of Judah?
The writer said still later,
“For if He were on earth, He would not be a priest, since there are priests who offer the gifts according to the law…” (Hebrews 8.4).
Therefore, Jesus is not a priest on the earth, rather He performs His priestly duties in heaven, because the Law of Moses did not apply to the inhabitants of heaven, but to Israel on earth.
The High Priesthood of Jesus Christ resembles that of Melchizedek and not that of Aaron, because the priesthood of Jesus does not depend upon from whom He descended, nor did He inherit the position from a priest who died before Him, nor shall He ever give up the position.