I recently read this article by Daniel Peterson regarding the Doctrine of Exaltation and how it has been taught by Joseph Smith via revelation, even before the founding of The Church of Jesus Christ of Latter Day Saints.
Starting with a passage from The Book of Mormon translated by Joseph Smith in the late 1820’s, The Book of Mormon describes the Savior’s visit to the America’s. This scripture is Jesus speaking to the Three Nephites in 3 Nephi:
“Ye have desired that ye might bring the souls of men unto me, while the world shall stand. And for this cause ye shall have fulness of joy; and ye shall sit down in the kingdom of my Father; yea, your joy shall be full, even as the Father hath given me fulness of joy; and ye shall be even as I am, and I am even as the Father; and the Father and I are one.” (3 Nephi 28:9-10)
He teaches his disciples that they will become as He and The Father are, and that they will become one.
Later on, Joseph Smith recieved a revelation in 1832 regarding exaltation:
“They are they into whose hands the Father has given all things — They are they who are priests and kings, who have received of his fulness, and of his glory; and are priests of the Most High, after the order of Melchizedek, which was after the order of Enoch, which was after the order of the Only Begotten Son. Wherefore, as it is written, they are gods, even the sons of God — Wherefore, all things are theirs, whether life or death, or things present, or things to come, all are theirs and they are Christ’s, and Christ is God’s. And they shall overcome all things.” (Doctrine and Covenants 76:55-60)
Then just prior to his martyrdom, Joseph Smith expanded on the doctrine of exaltation even more in the 1844 King Follet Discourse:
“Here then is eternal life — to know the only wise and true God. You have got to learn how to make yourselves Gods in order to save yourselves and be kings and priests to God, the same as all Gods have done — by going from a small capacity to a great capacity, from a small degree to another, from grace to grace, until the resurrection of the dead, from exaltation to exaltation — till you are able to sit in everlasting burnings and everlasting power and glory as those who have gone before.”
Kudos to Daniel Peterson in putting this all together to demonstrate this evolving principle as Joseph Smith himself learned it “line upon line, precept upon precept”.