Lehi saw a vision of the tree. Afterward, he taught concerning the atoning Messiah. At the beginning of Nephi’s vision, he is told that he will see what his father saw. Modern readers can easily focus on the explanation of the symbols in the dream, and miss the fact that all of what Nephi relates is pertinent to what his father saw. Nephi will clearly supply more information than what his father did, but the two essential parts will be the same. Nephi will see the symbolic vision, and then see the meaning of the tree.
At this point, it is important to lay the foundation for how the Nephites understood God. If we understand their view of God, it will make what they say of God more understandable to modern readers. We do not typically recognize that the Nephite understanding was different from ours.
Nephi was literally a child of the Old World. As a Hebrew from those times, he believed in God, and his God was Jehovah. That will not change. In the last episode, we introduced a difference between the Son of God and the Most High God. Those were two figures in Hebrew theology. What is important for modern readers is that we see in the use of the terms Spirit of God, Son of God, and Most High God in Nephi’s writing a familiar triune [consisting of three in one] that we call the Godhead. While Nephi would have understood these separate concepts, they were not necessarily behind his use of the word God.
The Son of the Most High God was Jehovah, and Jehovah was assigned as the God of Israel. Israel had no other God. They covenanted with Jehovah. They prayed to Jehovah. While they had record of the Most High God, they did not deal with the Father God, but with Jehovah.
Latter-day Saints understand that there is a difference between who we were in the pre-mortal life and who we are in mortality. In the premortal life, Jehovah was God of Israel. We understand Jehovah as the premortal Jesus. This, that God, Jehovah, came to earth. When the Spirit tells Nephi that he will “behold a man descending out of heaven … and will bear record that it is the Son of God,” Nephi is being told that God himself—Jehovah himself—will descend to become a man, a man we know as Jesus.