The Book of Mormon, Mosiah 27:31

31 Yea, every knee shall bow, and every tongue confess before him. Yea, even at the last day, when all men shall stand to be judged of him, then shall they confess that he is God; then shall they confess, who live without God in the world, that the judgment of an everlasting punishment is just upon them; and they shall quake, and tremble, and shrink beneath the glance of his all-searching eye.

The Doctrine and Covenants, Section 88:103-104

103 And another trump shall sound, which is the fifth trump, which is the fifth angel who committeth the everlasting gospel–flying through the midst of heaven, unto all nations, kindreds, tongues, and people;

104 And this shall be the sound of his trump, saying to all people, both in heaven and in earth, and that are under the earth–for every ear shall hear it, and every knee shall bow, and every tongue shall confess, while they hear the sound of the trump, saying: Fear God, and give glory to him who sitteth upon the throne, forever and ever; for the hour of his judgment is come.

Conference Report, John Taylor, October 1903

I tell you the time will come when every principle that was revealed to Joseph Smith, the Prophet, in this last dispensation, will be adopted, one by one, until every knee shall bow and every tongue confess; that Jesus is the Christ, and that Joseph Smith is a prophet of the living God.

Conference Report, Ray L. Pratt, April 1920

[E]very knee shall bow to Christ, and every tongue confess that he is the Savior of the world, so do I expect to see the time come when every tongue will confess this great truth, that Joseph Smith is a prophet of God. Men may not confess it because they want to. All men that will confess it, perhaps, will not repent of their sins; but conditions will be brought about by the calamities that the Lord will send upon the world and his punishments meted out to men, until men cannot deny, but will confess, even though they will not repent, that these things are true.

Conference Report, Ray L. Pratt, October 1921

The decree has gone forth that every knee shall bow and every tongue confess that Jesus is the Christ, and it will come. Whether it will come because they accept the testimony of the servants of the Lord, or whether they be brought low by the judgments of God, the people of this world will acknowledge him and bow in reverence and worship before him.

Journal of Discourses, Brigham Young 12:54

Now when Zion is built up and reigns, the question may arise with some, will all be Latter-day Saints? No. Will there be this variety of classes and faiths that we now behold? I do not know whether there will be as many, or whether there will be more. …. In the millennium men will have the privilege of being Presbyterians, Methodists or Infidels, but they will not have the privilege of treating the name and character of Deity as they have done heretofore. No, but every knee shall bow and every tongue confess to the glory of God the Father that Jesus is the Christ.

Journal of Discourses, John Taylor 11:14

We look forward to the time, and try to help it on, when God will assert his own right with regard to the government of the earth; when, as in religious matters so in political matters, he will enlighten the minds of those that bear rule, he will teach the kings wisdom and instruct the senators by the Spirit of eternal truth; when to him “every knee shall bow and every tongue confess that Jesus is the Christ.” Then “shall the earth be full of knowledge, like as the waters cover the sea.” Then shall the mists of darkness be swept away by the light of eternal truth. Then will the intelligence of Heaven beam forth on the human mind, and by it they will comprehend everything that is great, and good, and glorious.

Journal of Discourses, John Taylor 11:49

They [the Scriptures] speak of a time when the Lord will reign, when His empire will be universal; when His dominion “shall extend from the rivers to the ends of the earth,” and when, “to Him every knee shall bow and every tongue confess.” They speak of, “The law of the Lord going forth from Zion, and the word of the Lord from Jerusalem.” They speak of a time when, “He shall smite the nations as with a rod of iron, and when he will dash them to pieces like a potter’s vessel,” and when He will introduce a new order of things.