By him, and through him, and of him, the worlds are and were created, and the inhabitants thereof are begotten sons and daughters unto God

-thus Joseph Smith and Sidney Rigdon

Worlds, plural.  He is the savior of multiple worlds.

But I want to focus on the begotten part.  There is a lot of interesting mysticism in the scriptures about how we becomes sons and daughters of Christ, how the Son is the Father and so on.  But this revelation first emphasizes the Son’s status as the Begotten of the Father and then says that we are begotten sons and daughters of Father through the Son.  To me, the obvious answer is just that we take on Christ’s identity.  We are part of Christ, we are the body of Christ, and so in becoming Him, we become what He is–the Son of God, the Daughter of God.