|The Mormon Church has always maintained that the keys and the authority of the priesthood were given to the Council of the Twelve Apostles during the early days of the Church, so that, if the prophet should die, all the keys and authority could still be passed on.Revelation given to Joseph Smith on March 28, 1835, supports the fact that the quorum of the Twelve Apostles combined holds all the keys. “They form a quorum, equal in authority and power to” the presidency.” This same idea is reinforced in Doctrine and Covenants 112:30 in a revelation received on July 23, 1837. “For unto you, the Twelve, and those, the First Presidency, who are appointed with you to be your counselors and your leaders, is the power of this priesthood given, for the last days and for the last time.” On January 19, 1841, Brigham Young was called to be the president of the Twelve Apostles. On August 16 of the same year, in a special conference held in Nauvoo, Joseph Smith presented revelation that the Twelve are called to stand next to the First Presidency in the duties of the kingdom. This revelation was voted on by the members of the Church and put into action. All of these events support the fact that Joseph Smith gave all of the keys necessary to carry out the needs of the Church to the Twelve, and that it was God’s intent to have the Twelve govern in the event of the death of the prophet.During the winter of 1843 and 1844, tension was growing in Nauvoo. Enemies of the Prophet Joseph Smith were plotting to assassinate him, but also during this time, Joseph met often with the Twelve in a room above the red brick store. Of these meetings, Parley P. Pratt recorded,
“This great and good man [Joseph Smith] was led, before his death, to call the Twelve together, from time to time, and to instruct them in all things pertaining to the kingdom, ordinances, and government of God. He often observed that he was laying the foundation, but it would remain for the Twelve to complete the building. Said he, ‘I know not why; but for some reason I am constrained to hasten my preparations, and to confer upon the Twelve all the ordinances, keys, covenants, endowments, and sealing ordinances of the priesthood … for, said he, the Lord is about to lay the burden on your shoulders and let me rest awhile; and if they kill me … the kingdom of God will roll on, as I have now finished the work which was laid upon me, by committing to you all things for the building up of the kingdom according to the heavenly vision, and the pattern shown me from heaven.’ ”
On June 27, 1844, Joseph Smith was killed in Carthage. On August 8, a congregation assembled. Sidney Rigdon, a counselor in the First Presidency, spoke for some time about being appointed guardian of the Church. Later that same day Brigham Young spoke on behalf of all the Twelve. Many in the congregation bore testimony that while he was speaking, he looked and sounded like Joseph Smith. This led many to support the proposal to have the Twelve lead the Church. Because the Twelve held all the keys, they were able to confer all of them on Brigham Young, when he was ordained to be the Prophet. The keys of the priesthood have been handed down from John the Baptist, and the Apostles Peter, James, and John, as well as other heavenly messengers, to Joseph Smith and down through the other Presidents of the Church in an unbroken chain.
1 Section 107:24. Doctrine and Covenants.