Gen 12: 1-3 Now the Lord said to Abram, “Go from your country and your kindred and your father's house to the land that I will show you. And I will make of you a great nation, and I will bless you and make your name great, so that you will be a blessing. I will bless those who bless you, and him who dishonors you I will curse, and in you all the families of the earth shall be blessed.”
Is this promise for physical descendants of Abraham (Jews) only? Is it fulfilled only in the spiritual descendants of Abraham (the church)? Or is there a dual fulfillment that includes both Jews and the Christian church?
The promises (note that it is plural) given to Abraham were two-fold. There was the promise of birthright and the promise of the Sceptre (race and grace)...
Notice that God promised two distinct things...
Gen 12:1 Now the LORD had said unto Abram, Get thee out of thy country, and from thy kindred, and from thy father's house, unto a land that I will shew thee:
Gen 12:2 And I will make of thee a great nation, and I will bless thee, and make thy name great; and thou shalt be a blessing:
Ntional blessings.
Gen 12:3 And I will bless them that bless thee, and curse him that curseth thee: and in thee shall all families of the earth be blessed.
Spiritual blessings. As we continue to read we see these blessings refined. Reaffirmation of the birthright...
Gen 15:17 And it came to pass, that, when the sun went down, and it was dark, behold a smoking furnace, and a burning lamp that passed between those pieces.
Gen 15:18 In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:
Gen 15:19 The Kenites, and the Kenizzites, and the Kadmonites,
Gen 15:20 And the Hittites, and the Perizzites, and the Rephaims,
Gen 15:21 And the Amorites, and the Canaanites, and the Girgashites, and the Jebusites.
Gen 17:3 And Abram fell on his face: and God talked with him, saying,
Gen 17:4 As for me, behold, my covenant is with thee, and thou shalt be a father of many nations.
Gen 17:5 Neither shall thy name any more be called Abram, but thy name shall be Abraham; for a father of many nations have I made thee.
Gen 17:6 And I will make thee exceeding fruitful, and I will make nations of thee, and kings shall come out of thee.
Gen 17:7 And I will establish my covenant between me and thee and thy seed after thee in their generations for an everlasting covenant, to be a God unto thee, and to thy seed after thee.
Gen 17:8 And I will give unto thee, and to thy seed after thee, the land wherein thou art a stranger, all the land of Canaan, for an everlasting possession; and I will be their God.
Now here we see the promises made unconditional...
Gen 22:16 And said,
By myself have I sworn, saith the LORD, for because thou hast done this thing, and hast not withheld thy son, thine only son:
Gen 22:17 That in blessing I will bless thee, and in multiplying I will multiply thy seed as the stars of the heaven, and as the sand which is upon the sea shore; and thy seed shall possess the gate of his enemies;
Gen 22:18 And in thy seed shall all the nations of the earth be blessed; because thou hast obeyed my voice.
Again, birthright and Sceptre.
Now we see the birthright promise separated from the Sceptre promise...
Gen 48:14 And Israel stretched out his right hand, and laid it upon Ephraim's head, who was the younger, and his left hand upon Manasseh's head, guiding his hands wittingly; for Manasseh was the firstborn.
Gen 48:15 And he blessed Joseph, and said, God, before whom my fathers Abraham and Isaac did walk, the God which fed me all my life long unto this day,
Gen 48:16 The Angel which redeemed me from all evil, bless the lads; and let my name be named on them, and the name of my fathers Abraham and Isaac; and let them grow into a multitude in the midst of the earth.
Gen 48:17 And when Joseph saw that his father laid his right hand upon the head of Ephraim, it displeased him: and he held up his father's hand, to remove it from Ephraim's head unto Manasseh's head.
Gen 48:18 And Joseph said unto his father, Not so, my father: for this is the firstborn; put thy right hand upon his head.
Gen 48:19 And his father refused, and said, I know it, my son, I know it: he also shall become a people, and he also shall be great: but truly his younger brother shall be greater than he, and his seed shall become a multitude of nations.
Gen 48:20 And he blessed them that day, saying, In thee shall Israel bless, saying, God make thee as Ephraim and as Manasseh: and he set Ephraim before Manasseh.
The birthright blessings are now conferred on Joseph (Ephraim and Manasseh) while the Sceptre (the promise of the King of Kings and grace) being placed squarely on Judah...
Gen 49:8 Judah, thou art he whom thy brethren shall praise: thy hand shall be in the neck of thine enemies; thy father's children shall bow down before thee.
Gen 49:9 Judah is a lion's whelp: from the prey, my son, thou art gone up: he stooped down, he couched as a lion, and as an old lion; who shall rouse him up?
Gen 49:10 The sceptre shall not depart from Judah, nor a lawgiver from between his feet, until Shiloh come; and unto him shall the gathering of the people be.
and also...
Heb 7:14 For it is evident that our Lord sprang out of Juda; of which tribe Moses spake nothing concerning priesthood.
There are two promises, race and grace, and the promises to Abraham cannot be understood without recognizing this.