The tree of life is symbolic of the love of God.
21 And the angel said unto me: Behold the Lamb of God, yea, even the Son of the Eternal Father! Knowest thou the meaning of the tree which thy father saw?
22 And I answered him, saying: Yea, it is the love of God, which sheddeth itself abroad in the hearts of the children of men; wherefore, it is the most desirable above all things.
23 And he spake unto me, saying: Yea, and the most joyous to the soul.
24 And after he had said these words, he said unto me: Look! And I looked, and I beheld the Son of God going forth among the children of men; and I saw many fall down at his feet and worship him.
25 And it came to pass that I beheld that the rod of iron, which my father had seen, was the word of God, which led to the fountain of living waters, or to the tree of life; which waters are a representation of the love of God; and I also beheld that the tree of life was a representation of the love of God.
President Boyd K. Packer said:
“Lehi had a vision of the tree of life. His son Nephi prayed to know its meaning. In answer, he was given a remarkable vision of Christ . . . That vision is the central message of the Book of Mormon. The Book of Mormon is in truth another testament of Jesus Christ.”
(“The Things of My Soul,” Ensign, May 1986, 60, 61.)