 He taught that the reason that mankind is on earth is to progress, and that this life is but a single step in our eternal progression, and part of the Plan of Salvation.He taught that many of those who enter the Celestial Kingdom may be worthy for Deification (Exaltation), where mankind, as children of God, can eventually become co-inheritors with Christ and inherit all that the Father has — in simple terms, to become like God.Smith taught that families are a central part of God's plan for mankind, and an important part of growth and progression.