In the plan of salvation, it is contemplated that all children, regardless of race, color, or creed, who die before they reach the age of accountability, eight years, are saved in the celestial kingdom through the atonement of Jesus Christ. The voice of the Lord to Joseph Smith was heard to say in the vision “And I also beheld that all children who die before they arrive at the years of accountability, are saved in the celestial kingdom of heaven.” This is what Jesus meant when He blessed little children and said that they were of the kingdom of heaven.
As there are three kingdoms of glory—celestial, terrestrial, and telestial—so there are many gradations with these great heavens. In the celestial kingdom there are three heavens or degrees … Latter-day saints are prone to refer to the attainment of the celestial kingdom as the highest objective available in the gospel plan … If, in using the term celestial glory or kingdom, is meant exaltation in that kingdom, then that is the highest objective. On the other hand, if one ignores that there are different degrees in the celestial kingdom and the highest “heaven” is possible only by obedience to all of the commandments, including temple marriage and its covenants, the expression is misleading.
Satan and his followers will be cast into outer darkness to remain forever. The earth will then become celestialized as the habitat of celestial beings, while other resurrected persons will reside on some other world.