B. H. Roberts cites the BOM as containing ancient prophecies.
B. H. Roberts, Speech, October 1922, in Ninety-Third Semi-Annual Conference of the Church of Jesus Christ of Latter-day Saints (Salt Lake City: The Church of Jesus Christ of Latter-day Saints, 1922), 14–20
The Lord made certain promises in ancient times concerning the land of Zion—North and South America. We are told in the book of Ether that when the floods receded from this land, it became a choice land unto the Lord, a land which he would dedicate to freedom, and hence, to free institutions, and unto a righteous people. That is the information we get from our Book of Mormon. And later on, in the history of this book, we get further information as to the decrees of God concerning this land.
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In the fore part of the Book of Mormon—in the writings of Nephi, there is a message similar in importance. It is in Second Nephi—the first chapter, as I now remember it; and it there describes in effect, the rise of a great Gentile nation that shall be used as an instrument in the hands of God in restoring Israel unto their possessions in this land. There is no escaping the inference that there is held in the mind of the prophet the nation of the United States, and that it should become as a nursing father and mother to the remnants of Israel in this land, and should be instrumental in bringing to pass, in a large way, the will of God with reference to the accomplishment of his purposes in the land. In other words, it is quite clear from the Book of Mormon, that God has designed to bless the Gentile nations upon this land of Zion, if only they will be true to him and to the great principles of righteousness that enter into the very attributes of God. And, on the other hand, dire calamity is predicted upon the proud Gentile nation in this land if it fails God as an instrument in the accomplishment of his high purposes.
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I want to suspend reading the remainder of this passage for a moment, while I call your attention to the fact that the conditions here named, as to the Gentile nation in this land, are wonderfully fulfilled. When this Book of Mormon came forth in 1830, there were about twelve millions of people in the United States; now we have nearly three times that number in the Eastern States Mission alone; and in all the United States, we exceed by considerable, a hundred millions within the borders of continental United States. It was a very bold prediction to write in a book in 1830, when the United States occupied practically only the Atlantic seaboard, and the Ohio valley, to some extent—it was a rather bold prediction to write in a book the prophesy that this Gentile nation—the United States—would be "exalted above all other nations, and above all the people of the whole earth." But witness its fulfilment today ! It is true, and this nation, had in mind when this prediction was sent forth in our modern language, was regarded merely as an experiment in government, and no such future was ever dreamed of for it as is here predicted, and now fulfilled. And also the other and the sadder part of it; namely—that they would not only be lifted up in power above all other nations, but also they would be filled with all manner of lyings and deceits, and mischiefs and hypocrisies and murders and priestcrafts and whoredoms and of secret abominations—"And if they do all these things, and shall reject my gospel—" and behold, that is what the people of the United States did when they rejected from habitation among them, the Church of Jesus Christ of Latter-day Saints, and expatriated the membership thereof, so that they were under the necessity of finding a refuge in a land, which, at the time our fathers entered it—The Salt Lake Valley—was no part of the United States of America but was Mexican territory.
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I bear witness to you, from my heart, that the inspiration of God has dictated to our President the Key-note words of warning in this conference of the Church of Jesus Christ of Latter-day Saints. May we sense the responsibility resting upon us as a great missionary Church in the earth, charged with the solemn duty of calling men to repentance, and warning nations against the fate that awaits the nation that lapses into lawlessness, crime, and unrighteousness; for God, in these things will not be mocked. May we sense our duty and responsibility is my prayer in the name of Jesus. Amen.