After his return from the defeat of Chedorlaomer and the kings who were with him, the king of Sodom went out to meet him at the Valley of Shaveh (that is, the King’s Valley). And Melchizedek king of Salem brought out bread and wine. (He was priest of God Most High.)  And he blessed him and said,

“Blessed be Abram by God Most High,
     Possessor of heaven and earth;
       and blessed be God Most High,
    who has delivered your enemies into your hand!”

And Abram gave him a tenth of everything.

A King of Salem (later Jerusalem) who was priest of the God Most High, existed before the “ministry”, such that it was at this point, of Abram. This Melchizedek (from Hebrew Malchi “king” and Zedek “righteous”) presents Abram with bread, wine, and a blessing. Abram responds with a tithe. The richness of this passage is betrayed by the paucity of time given to it in modern evangelicalism. 

What do we take away? One, the priestly ministry of the God Most High was not exclusive to Abram. There were believers in God before, and these believers did not simply exist in a state of family devotions. They had priests, if it is assumed Melchizedek was not the only one in the world at that time, that in some sense shepherded them in their worship. What was the worship of the One True God under the guidance of Melchizedek like? We may never know, except that it was distinct from the calling of Abram.

Secondly, we see the liturgical pattern of bread, wine and offerings is not innovative in the least. We see later that wine, when it replaced the “strong drink” libation offering in the Tabernacle cultus, is a kingly drink, suitable for rule and rest. A symbol of peace brought by victory.

Lastly, we later learn in Genesis 17:23 that all the men, not just Abraham, who were of his household were circumcised. God had said, 

Any uncircumcised male who is not circumcised in the flesh of his foreskin shall be cut off from his people; he has broken my covenant.

This means that the Abrahamic people were never exclusively a genetic group, defined by bloodline. Bloodlines, like families, provided the “scaffolding” as it were to the structure, but did not define the boundaries. The Hebrews were from the beginning a covenantal people of allied assimilation united under the calling of Abram to draw the peoples of the world to the One True God. Similarly reflecting the covenantal nature of the “nation”, Jacob later went down to Egypt, and so many “Hebrews” went that they needed the whole land of Goshen, yet the bible only lists 70 actual “blood” relatives of Abraham.

From the beginning, the Hebrews were a people of COVENANT, not of race. The “family princes” formed a scaffolding in a way to build a priestly people. This was true of the tribes as well, as house servants were considered tribal members. These few thousand became over 2 million by the time of the Exodus. Only a few would have direct Abrahamic lineage. Caleb the Kenizzite, a gentile, is sent by Moses and accompanies Joshua on the famous mission to the land of Canaan.

Later, in the time of David and Solomon, many gentile converts to the God of Israel were added. Uriah the Hittite is a memorable example. Were these special cases? No, for the Psalms include these exhortations from Psalm 115:

O Israel, trust in the Lord;
He is their help and their shield.
O house of Aaron, trust in the Lord;
He is their help and their shield.
You who fear the Lord, trust in the Lord;
He is their help and their shield.

The Lord has been mindful of us;
He will bless us;
He will bless the house of Israel;
He will bless the house of Aaron.
He will bless those who fear the Lord,
Both small and great.

This passage includes three distinct groups; the people of Israel, the priests specifically, and the Gentiles who are God-fearers (believers who don’t convert to Judaism but are “saved” in our parlance).

Furthermore, we see in Psalms 128 the same idea when it says 

Blessed is everyone who fears the LORD, who walks in His ways.

This is not exclusive to the circumcised. Consequently, we can see, Israel was not exclusive to those of Abraham’s DNA, and salvation continued to be available to anyone who trusted in the One True God, Yahweh / (Jehovah).

From: Just what is Israél? Ronald Dodson (An extract)