'"[6] According to LDS restorationist beliefs, a period of universal apostasy had followed the death of the Christ's original Twelve Apostles.
[7] Without such apostolic prophets left on the earth with possession of legitimate priesthood authority, many of the true teachings and practices of Christianity were lost.
Joseph Smith and Oliver Cowdery[10] said that the apostles Peter, James, and John appeared to them in 1829 and conferred upon them the Melchizedek priesthood[11] and with it "the keys of the kingdom, and of the dispensation of the fullness of times.
[18] When the Quorum of the Twelve has failed to achieve unanimity with regard to any matters brought before it, a decision is made to wait prior to taking action.
Notwithstanding consideration of other scenarios on occasion, in every succession to date, church leadership has passed to the individual considered to have the most senior tenure.