In the King Follett Sermon, Joseph Smith stated:
In order to understand the subject of the dead, for consolation of those who mourn for the loss of their friends, it is necessary we should understand the character and being of God and how He came to be so; for I am going to tell you how God came to be God. We have imagined and supposed that God was God from all eternity. I will refute that idea, and take away the veil, so that you may see.
These ideas are incomprehensible to some, but they are simple. It is the first principle of the gospel to know for a certainty the character of God, and to know that we may converse with Him as one man converses with another, and that He was once a man like us; yea, that God himself, the Father of us all, dwelt on an earth, the same as Jesus Christ Himself did; and I will show it from the Bible....
Here, then, is eternal life—to know the only wise and true God; and you have got to learn how to be gods yourselves, and to be kings and priests to God, the same as all gods have done before you, namely, by going from one small degree to another, and from a small capacity to a great one; from grace to grace, from exaltation to exaltation, until you attain to the resurrection of the dead, and are able to dwell in everlasting burnings, and to sit in glory, as do those who sit enthroned in everlasting power. And I want you to know that God, in the last days, while certain individuals are proclaiming His name, is not trifling with you or me.
The King Follett Sermon
“Man is a god in embryo and has in him the seeds of godhood, and he can, if he will, rise to great heights.”
Teachings of Presidents of the Church: Spencer W. Kimball, (2006)
Doctrine and Covenants 88
107 And then shall the angels be crowned with the glory of his might, and the saints shall be filled with his glory, and receive their inheritance and be made equal with him.
Doctrine and Covenants 132
20 Then shall they be gods, because they have no end; therefore shall they be from everlasting to everlasting, because they continue; then shall they be above all, because all things are subject unto them. Then shall they be gods, because they have all power, and the angels are subject unto them.