If we agree that Melchizedek was a real historical person, the next interesting question is how to interpret Hebrews 7:3:
“Without father or mother, without genealogy, without beginning of days or end of life, resembling the Son of God, he remains a priest forever.”
The interpretation I propose is the following:
Melchizedek’s episode in Genesis 14:18 refers to the apparition of a true man, who was already in Heaven seeing God “as He is”, and therefore was like the Son of God (1. John 3:2). But this entails that Melchizedek was created along with “Adam and Eve” before these sinned, and did not follow “Adam and Eve” in disobeying God’s commandment. Accordingly Melchizedek was taken by God directly into Heaven to see God and thereby became “like the Son of God”. He then came again and appeared to Abraham as “Righteous King” and “Priest of God Most High” (Genesis 14:18) to establish the Order according to which Jesus Christ “is Priest for ever” (Psalm 110:4).
Since this interpretation is tightly related to other arguments in this thread I would like to propose we continue this discussion here.