The reason for all the remarkable changes in the new world of peace is the overflowing knowledge of the Lord, meaning that he will be seen and known and that the knowledge that he has, his wisdom, understanding, counsel, judgment, righteousness, equity, and faithfulness will be available to all his creations. They will not only know about him but will know him.
Elder Orson Pratt taught that “the earth will be made new, and great knowledge will be imparted to the inhabitants thereof, as predicted in the 11th chapter of the prophecy of Isaiah. The knowledge of God will then cover the earth as the waters cover the mighty deep. There will be no place of ignorance, no place of darkness, no place for those that will not serve God. Why? Because Jesus, the Great Creator, and also the Great Redeemer, will be himself on the earth, and his holy angels will be on the earth, and all the resurrected Saints that have died in former dispensations will all come forth, and they will be on the earth. What a happy earth this creation will be, when this purifying process shall come, and the earth be filled with the knowledge of God as the waters cover the great deep!” 64