In the spring of 1820, 14-year-old Joseph Smith was searching for the true Church of Jesus Christ when he read a passage in the Bible: “If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him” (James 1:5; see also Joseph Smith—History 1:11–12). With simple, unwavering faith, young Joseph followed the counsel in that passage. He went alone to a grove of trees, where he prayed to know which church he should join. In answer to his prayer, God the Father and Jesus Christ appeared to him. Among other things, They told him that he should join none of the churches then in existence. (See Joseph Smith—History 1:13–20.)
As Joseph Smith proved his worthiness, he was given a divine mission as a prophet of God. Through him, the Lord accomplished a great and marvelous work that included bringing forth the Book of Mormon, restoring the priesthood, revealing precious gospel truths, organizing the true Church of Jesus Christ, and establishing temple work. On June 27, 1844, Joseph and his brother Hyrum were killed in an attack by an armed mob. They sealed their testimonies with their blood.
For your testimony of the restored gospel to be complete, it must include a testimony of Joseph Smith’s divine mission. The truthfulness of The Church of Jesus Christ of Latter-day Saints rests on the truthfulness of the First Vision and the other revelations the Lord gave to the Prophet Joseph. President John Taylor, the third President of the Church, wrote, “Joseph Smith, the Prophet and Seer of the Lord, has done more, save Jesus only, for the salvation of men in this world, than any other man that ever lived in it” (D&C 135:3).