Melchizedek is more of a title than a personal name. The title comes from two Hebrew words, the first being melek meaning "king" and the second which is tsedeq or "righteousness" (Strong's #H4442). In Genesis 14, this person is labeled a priest and the king of Salem (the word Salem means "peace"). This makes him both the King of Righteousness and Peace (Hebrews 7:2).
The first Biblical reference to this person is in Genesis 14:18 where it states, "Then Melchizedek king of Salem brought out bread and wine; he was the priest of God Most High." This person was the epitome of righteousness, and since no human is inherently righteous, it is evident that he could not be human. If he were human, he would have been a sinner like Aaron the High Priest or anyone else.
What did Paul teach?
The Apostle Paul, in the book of Hebrews, makes some startling statements about this person.
For this Melchisedec (Melchizedek), King of Salem, Priest of the Most High God, Who met Abraham as he was returning from his slaughter of the kings, and blessed him,
And to Whom Abraham gave a tenth part of all; on the one hand, being interpreted King of Righteousness; and on the other hand, King of Salem, which is King of Peace;
Without father, without mother, without genealogy; having neither beginning of days, nor end of life; but having been made like the Son of God, remains a Priest forever (after the Order of Melchizedek, Hebrews 7:1 - 3).
Paul reveals to us some of the most important traits of Melchizedek, all of which rule out that he was a mortal human. He is clearly describing someone who is a member of the Godhead.
The person Paul describes as being the priest of the Most High God (Hebrews 7:1) is none other than a pre-incarnate appearance of Jesus Christ. Our Savior himself stated that not only did he exist before Abraham but that the "father of the faithful" also rejoiced to learn about his future efforts as man's Redeemer (John 8:56, 58)!
Similarities
Notice the following similarities between Melchizedek (the king of Salem) and Christ. They are both Kings over a kingdom. It is stated regarding Jesus, "Your throne, O God, is forever and ever; a scepter of righteousness is the scepter (symbol) of Your kingdom" (Hebrews 1:8 - 9).
The book of Revelation states that our Savior is the "Lord of lords, and King of kings" (Revelation 17:14). Clearly, both Melchizedek and Jesus and are rulers ordained by the Eternal. Note also that both of them are considered High Priests. No one can take this honor upon himself (Hebrews 5:1, 4).
The Bible reveals that Christ did not glorify Himself to be made our heavenly high priest but was called to do so (Hebrews 5:5 - 6). He was given this exalted position since salvation was not attainable through the Levitical priesthood (Hebrews 7:11).
Who is he?
Who is Melchizedek? He is none other than Jesus Christ, made a Priest forever by an oath of the Most High God (Hebrews 7:20 - 21). His righteousness that is manifested in the true saints of God (Romans 8:4). The church shares in the priesthood of Christ and the resurrected saints will, like Him, forever be kings and priests (Revelation 5:10).