When the Savior Jesus Christ returns there will be major changes to the earth, animals and mankind. All changes will be blessings and almost beyond human power to comprehend, so different from our experience.
Earthly Changes
Mountains Made Low and the Valleys Raised Up
“Every valley shall be exalted, and every mountain and hill shall be made low: and the crooked shall be made straight, and the rough places plain: And the glory of the LORD shall be revealed, and all flesh shall see it together: for the mouth of the LORD hath spoken it.” (Isaiah 40: 4-5 in the Old Testament)
John the Baptist preached, “Every valley shall be filled, and every mountain and hill shall be brought low; and the crooked shall be made straight, and the rough ways shall be made smooth;”
(Luke 3: 4-5 in the New Testament)
The Land Continents Brought Back together
Following the flood of the earth and after Noah, the earth was divided.
“And unto Eber were born two sons: the name of one was Peleg; for in his days was the earth divided; and his brother’s name was Joktan.” (Genesis 10: 25 in the Old Testament)
When the Savior returns, “He shall command the great deep, and it shall be driven back into the north countries, and the islands shall become one land; And the land of Jerusalem and the land of Zion shall be turned back into their own place, and the earth shall be like as it was in the days before it was divided.”
(Doctrine & Covenants 133: 23-24 p. 275)
The Earth will be Renewed and Receive its Paradisiacal Glory
It appears that the earth will be taken out of its present orbit in order to be able to bring it back to the conditions of the Garden of Eden. “Therefore I will shake the heavens, and the earth shall remove out of her place, in the wrath of the LORD of hosts, and in the day of his fierce anger.”
(Isaiah 13: 13 in the Old Testament)
“For the LORD shall comfort Zion: he will comfort all her waste places; and he will make her wilderness like Eden, and her desert like the garden of the LORD; joy and gladness shall be found therein, thanksgiving, and the voice of melody.” (Isaiah 51: 3 in the Old Testament)
“Throughout the Millennium, the process of regeneration will continue…the earth, relieved in great measure from the curse of the fall, shall yield bounteously to the husbandman; and the planet shall be redeemed. The final stages of this regeneration of nature will not be reached until the Millennium has run it’s blessed course.” (The Articles of Faith p 377)
Animal Changes
The animals shall mingle together in peace. “The wolf and the lamb shall feed together, and the lion shall eat straw like the bullock: and dust shall be the serpent’s meat. They shall not hurt nor destroy in all my holy mountain, saith the LORD.” (Isaiah 65: 25 in the Old Testament)
“And then shall the wolf dwell with the lamb; and the leopard shall lie down with the kid, and the calf, and the young lion, and the fatling, together; and a little child shall lead them. And the cow and the bear shall feed; their young ones shall lie down together; and the lion shall eat straw like the ox.” (2 Nephi 30: 12-13 p. 112 in the Book of Mormon)
Mankind (Mortal) Changes
Physical bodies of those living on earth during the millennium will not be subject to the same diseases that attend us in our present existence. Men and women in that day will still be mortal and children will be born to them, but death cannot intervene to cause a separation of body and spirit.
“There shall be no more thence an infant of days, nor an old man that hath not filled his days: for the child shall die an hundred years old…” (Isaiah 65: 20 in the Old Testament)
“And there shall be no sorrow because there is no death. In that day an infant shall not die until he is old; and his life shall be as the age of a tree; And when he dies he shall not sleep, that is to say in the earth, but shall be changed in the twinkling of an eye, and shall be caught up, and his rest shall be glorious.”
(Doctrine & Covenants 101: 29-31 p. 197)