The dispensation of the fulness of times has the divine mandate to prepare the world for the Second Coming. A central part of that role is to gather the dispersed of Zion and the willing and honest among the Gentiles unto Christ, to receive the saving principles and ordinances of the gospel. The Prophet and preparer of this, the final dispensation, was Joseph Smith:
Joseph Smith was a messenger sent before the face of the Lord to prepare a people on earth for that day which will be both great and dreadful (Malachi 3:1; 3 Nephi 24:1; JS—H 1:36). For that matter, the gospel plan restored through him—the new and everlasting covenant—was dispensed to earth to serve a preparatory function. “I have sent mine everlasting covenant into the world,” the Savior declared, “to be a light to the world, and to be a standard for my people, and for the Gentiles to seek to it, and to be a messenger before my face to prepare the way before me” (D&C 45:9; italics added). (Joseph Fielding McConkie and Robert L. Millet, Doctrinal Commentary on the Book of Mormon, 4 vols. [Salt Lake City: Bookcraft, 1987–1992], 2:71)