According to Richard Anthony, the story of the Father and the firstborn was given to us for the first time in greatest detail with Abraham. . . . As Adam was firstborn son, and Noah a firstborn son, Abraham became a firstborn son also. It was to be through Abraham's ministry that God's name would be known in the earth forever (Abraham 1:19).
The firstborn of the Father, Jehovah, made a promise to Abraham that:
1. He would make him a great nation.
2. He would bless him above measure, (beyond man's ability to measure).
3. His name would be great among nations.
4. He would be a blessing to his seed who should bear this priesthood and ministry.
5. God would bless those that bless Abraham, and curse those who curse him, (curse those who pay no heed to the teachings of Abraham and His seed)
6. Through Abraham's literal seed, the Firstborn Son of God would be born to bless all the earth with the gospel of salvation and eternal life. (Abraham 2:10-11)
As Adam started life on this earth, and Noah started life again after the flood, so Abraham started in the likeness of Adam and Noah. Rather than destroy all evil with another flood, God chose to scatter the righteous seed among these "desolate" nations so that the blessings of the covenant people might come to all. This is part of the great plan of Mercy, from before the foundation of the world.
[Richard D. Anthony, Isaiah and Joseph, p. 30, unpublished] [See the commentary on 1 Nephi 15:18, 22:9; Helaman 8:18; 3 Nephi 20:27; Mormon 5:20; Ether 13:11]