In the series “10 reasons why Melchizedek was actually the pre-incarnate Word of God” the following article is reason # 2.
Melchizedek is the King of Salem which is to say the King of Peace.
In Genesis 14 which gives a historical account of a conflict involving two groups of kings, the mysterious king of Salem named Melchizedek, who is thus far unaccounted for, suddenly and briefly appears in the narrative; and were he not described as “the priest of the Most high God” it would seem completely acceptable to assume that Salem was just another territory that was in the proximity of the other ones listed in Genesis 14:1-2. However, three observations make this assumption very problematic. The first is the fact that Melchizedek’s job as the priest of YAHWEH indicates that he was a heavenly and not an earthly priest (Hebrews 8:4); the second is the fact that there is no biblical record of such a territory contemporaneous to those of Genesis 14:1-2. The third and perhaps most devastating obstacle of all is that Hebrews 7:2 completely repudiates the idea that the word Salem was ever meant to describe a territory thus effectively disposing of any conversation concerning a Melchizedek-ruled city named Salem. Additionally, apart from Genesis 14:18, the word “Salem” is used only one other time in the Old Testament (Psalm 76:4) and there it poetically refers to the Millennial Jerusalem. Speaking on the identity of Salem, Dr. Henry Morris states:
[Psalm 76:4] is the only place in the Old Testament where the name of “Jerusalem” (“the City of Peace”) is abbreviated to “Salem” (or simply “Peace”). Since this psalm is looking forward to the millennium, when God “shall speak peace” (Zec_9:10) to all nations, and “out of Zion shall go forth the law, and the word of the Lord from Jerusalem” (Isa_2:3), the city may then be known simply as Salem…A number of modern archaeologists have speculated that the name Salem was actually “Salim,” a god of the Amorites, but this idea is entirely hypothetical and is explicitly contradicted by [Hebrews 7:2]. Similarly, it is commonly assumed that Salem was the original name of Jerusalem, but there is no other record of such a city at this time, either in archaeology or Scripture.
So again according to the Holy Spirit in Hebrews 7:2, the Salem of Genesis 14:18 was not a location but a title; namely, king of peace. Yet, some commentaries err on the side of blasphemy by calling Melchizedek a “Canaanite priest” or a “Canaanite king” living in an old “Canaanite city then called Salem” without any scriptural backing for such a position. Others (presumably due to Psalm 76:4) argue that Melchizedek was king of Jerusalem. For example:
[Melchizedek] bursts upon us as a priest-king, king of Salem, or Jerusalem, which we now know from discoveries in Egyptian records existed even in those very early ages
When Abraham was returning from victory over a group of invaders, he was met by Melchizedek, the ruler of the Canaanite city-state of Salem. (This appears to be the place later known as Jerusalem.)
Dr. Arnold Fructenbaum’s Ariel Ministries says:
Melchizedek was a type of Messiah but he was not a pre-incarnate Christ since every priest had to be human (Hebrews 5:1) and the Son was not human until the incarnation. Moreover, theophanies made their appearance and then disappeared after fulfilling their mission. They did not hold earthly offices such as king and priest of Jerusalem, which is what Melchizedek was. It is best just to see Melchizedek as a type of Messiah and leave it there.
The Ariel Ministries argument is bad for many reasons. The idea that Jerusalem is Melchizedek’s Salem is unacceptable because Ezekiel 16:3-4 makes Jerusalem a pagan entity at its birth; how could the king of righteousness preside over a province that would reek of unrighteousness for over 1000 years? Also, in spite of what the Ariel Ministries citation would have us believe, Hebrews 5:1 does not say that every priest has to be human. Hebrews 5:1 says: “For every high priest taken from among men is ordained for men in things pertaining to God, that he may offer both gifts and sacrifices for sins.” So we see that Hebrews 5:1 is not putting forth qualifications that must befall all high priests; rather, it is describing traits that befall high priests that are taken from among men. Obviously Jesus, the Lamb of God that was slain before the foundation of the world (Revelation 13:8) is perpetually a high priest (Hebrews 7:24) and yet so is Melchizedek (Hebrews 7:3) so we know from this fact alone that Melchizedek and Christ must be the same person. It is also instructive to realize that the bible doesn’t provide rules or restrictions that must apply to theophanies, so to appeal to such is to argue erroneously. Nevertheless, to claim that Melchizedek held “earthly offices such as king and priest of Jerusalem” is to conclude that Melchizedek, the king of righteousness whose priesthood brings about perfection, was actually the mediator of failure and unrighteousness since apart from Abraham and his household (Gen 18:19), none of the inhabitants of Canaan (prior to Israel) were recipients of the righteousness which is by faith.
Melchizedek was a Canaanitish prince, a worshipper of the true God, and in his peculiar history and character an instructive type of our Lord, the great High Priest
The best founded opinion seems to be that …[Melchizedek] was a principal person among the Canaanites and posterity of Noah, and eminent for holiness and justice, and therefore discharged the priestly as well as regal functions among the people…The way in which he is mentioned in Genesis would lead to the immediate inference that Melchizedek was of one blood with the children of Ham, among whom he lived, chief (like the king of Sodom) of a settled Canaanitish tribe.
Bob Utley states:
[Melchizedek] was a Gentile king/priest of the old Canaanite city then called Salem, which later became Jebus and then later Jerusalem…The city may have gotten its name from the Hebrew term shalom which means “peace.” … The city is called Salem in Genesis 14, but Psalms 76:2 relates it to Jerusalem (i.e., Zion), which was called Jebus during the Canaanite period. 
A Gentile king? But Jesus says in John 8:6 that only the Jews know Who they worship because salvation is of the Jews. How could Melchizedek the immortal priest of the Most High God be in league with the Gentiles before God officially appears to the Jews? Speaking to the Jews, Paul in Acts 13:46 confirms that the Word of God should first have been spoken to the Jews before the Gentiles. Why would the high priest of the Most High God be caught ministering unto Gentiles at this time? Isn’t Abraham said to be the father of those who would be saved by faith (Romans 4:11). In fact, Galatians 3:8 tells us that reason why the Gospel was preached unto Abraham was because He (i.e. the Scriptures) foresaw that God would justify the heathen through faith. And isn’t it true that recipients of the atonement afforded by the Melchizedek priesthood must come to God by faith (Hebrews 7:25)?
If all this is so then what other persons could Melchizedek have been ministering unto at this time besides Abraham? Paul says in Romans 11:30: “For as ye in times past have not believed God, yet have now obtained mercy through their unbelief.” Therefore the bible makes it clear that God went to the Jews first then to the Gentiles and It would seem that Romans 11:30 rules out any possible involvement of Melchizedek–Who’s priesthood brings about perfection (Hebrews 7:11, Hebrews 10:1-4)–with any gentile or pagan nations of that day. Besides, if this priesthood that brings about the perfection of its subjects (Hebrews 7:11) was in practice in the supposed city of Salem then where are those perfected citizens of Salem and why does God afterward introduce an inferior priesthood that can perfect no one (Hebrews 7:11)? Hebrews 7:19 tells us that the bringing in of a better hope (i.e. the Melchizedek Priesthood) brought about perfection but why does God bring in something better if that better thing already preceded what is being replaced?
Matthew Henry, whose’s conception of Melchizedek is not without flaws nevertheless asks an important question when he states:
The most commonly received opinion is that Melchizedek was a Canaanitish prince, that reigned in Salem, and kept up the true religion there; but, if so, why his name should occur here only in all the story of Abram, and why Abram should have altars of his own and not attend the altars of his neighbor Melchizedek who was greater than he, seem unaccountable.
Moreover, why would Melchizedek be King over a city that was later ruled and defiled by other pagan kings? If Salem is Jerusalem then you have a thousand years of pagan nations (culminating with the Jebusites) ruling over Melchizedek’s kingdom. The bible tells us that after defeating the Jebusites, king David made Jerusalem the capital city of Judah and of all Israel. For this reason, in certain verses of scripture Jerusalem is called the city of David. But why isn’t Jerusalem called the city of Melchizedek? After all, according to the “commonly received opinion”, both Melchizedek and David ruled over Jerusalem and Melchizedek in light of his title must certainly be deemed a greater king than David! If Melchizedek was king of Jerusalem in the time contemporaneous to Abraham then shouldn’t we also expect the Scriptures to proclaim that Christ would sit on Melchizedek’s throne instead of David’s? After all, (putting lineage aside) Melchizedek was a much greater king of Jerusalem than David. Yet, Melchizedek’s kingdom of Salem is apparently so insignificant that the scriptures do not think to provide any details about this supposed kingdom but instead chooses to undermine it by explaining it away as a title (Hebrews 7:2).
So, yet to be answered is the question of how a godly, immortal priest who sponsored a priesthood that brings about perfection could be confused with the likes of a Canaanite king? Agreeing with this analysis, Dr. Henry Morris’ Defender’s Study Bible also questions “how such a godly king and priest as Melchizedek could be ruling a city in such an ungodly land as Canaan and, why, if he did, Abram would have had no other contact with him.” The solution according to the same commentary is that “it seems better to take the words [of Hebrews 7:3] literally, in which case they could only be applicable to Christ Himself, appearing here to Abram in a theophany.”
Dr. Morris in his Defender’s Study Bible also argues that Jerusalem was anti-God from her very beginnings and could not thus be Salem by adding:
That Melchizedek’s Salem could never have been Jerusalem is evident especially from Ezekiel 16:2-4 [where Jerusalem is said to have been born of an Amorite and a Hittite]. God’s description of the birth and early growth of the city of Jerusalem, using the symbol of a woman for the city, makes it clear that her history was completely pagan until God Himself made it His “holy city” under David and Solomon. This fact seems to eliminate the possibility that Jerusalem was originally Salem, the “city of peace,” ruled by Melchizedek
In conclusion, it is clear that Salem was not a city at all but instead was the title of the second Person of the trinity who appeared to Abram in a theophany, namely, Yeshua the Messiah Who is also called the Word of God.
5. See notes on Psalms 76:4 & Hebrews 7:2, The Defender’s Study Bible, Henry M. Morris, Ph.D., LL.D., Litt.D.
6. See notes on Hebrews 7:1-3, The People’s New Testament (1891), B. W. Johnson
7. See notes on Melchizedek, Bridgeway Bible Dictionary, Don Fleming
8. http://www.ariel.org/qa/qmelchiz.htm, Ariel Ministries, Dr. Arnold Fructenbaum
9. See topic Melchizedek, Illustrated Bible Dictionary, M.G. Easton M.A., D.D.
10. See notes on Melchizedek, Cyclopedia Of Biblical, Theological And Ecclesiastical Literature, Rev John M’clintock, D.D., James Strong, S.T.D.
11. See notes on Hebrews 7:1-3, Bible Lessons International, Dr. Bob Utley
12. See notes on Genesis 14:17-20, Matthew Henry’s Commentary on the Whole Bible, Dr. Matthew Henry
13. [The meeting between Abraham and Melchizedek] was c.1000 years prior to David’s conquest of the city (2 Sam 5:6-10). See Hebrews 7, E. Melchizedek Like The Son Of God (7:1-3), The College Press NIV Commentary New Testament, David A. Fiensy, Ph.D., Jack Cottrell, Ph.D., Tony Ash, Ph.D.
14. See notes on Ezekiel 16:4, The Defender’s Study Bible, Henry M. Morris, Ph.D., LL.D., Litt.D.