Now mark another prophecy. “I heard a great voice,” says John, “from heaven, saying, ‘Come out of her, O my people!” Out of where? “Mystery Babylon, the Great”—out of this great confusion that exists throughout all the nations and multitudes of Christendom. “Come out of her, O my people, that ye partake not of her sins, that ye receive not of her plagues; for her sins have reached to the heavens, and God hath remembered her iniquities!” Is this being fulfilled? Do you see any indications of the people of God coming out from “Mystery Babylon the Great?” Yes, for forty-two years, and upwards, God has commanded his people, not by something devised by a congregation of divines, or by human ingenuity, but by a voice from heaven which has been published and printed, requiring all who receive the everlasting Gospel to come out from the midst of great Babylon. One hundred thousand Latter-day Saints, approximately speaking, now inherit these mountain regions. They are here because of this prediction of John, because of its being fulfilled, because of the voice that has come from heaven—the proclamation of the Almighty for his people to flee from amongst the nations of the earth. I need not say any more in regard to this prophecy; it is in the Bible, and is being fulfilled before the eyes of all people.
– Orson Pratt, 4/7/1872