The highest-ranking governing body in The Church of Jesus Christ of Latter-day Saints is the First Presidency, consisting of the president and his two counselors, or advisers. This three-man body supervises the work of the entire Church in all matters of policy, organization and administration.
The second-highest presiding body in Church government is the Quorum of the Twelve Apostles. Apostles serve under the direction of the First Presidency and have heavy administrative responsibilities to oversee the orderly progress and development of the Church throughout the world. The First Presidency and Twelve Apostles are regarded by Latter-day Saints as prophets who receive divine revelation and inspiration to guide the Church.
The appointment of a new president of the Church happens in an orderly way that — remarkably in today’s world — avoids any trace of internal lobbying for position or rank. Viewed by members as a divinely revealed process, it is devoid of electioneering whether behind the scenes or in public.
Moreover, it is not only the structure of Church organization that governs this process. There is also a deeply ingrained tradition in the Church that personal aspiration for leadership at any level is inappropriate. Instead, the emphasis is on personal worthiness and a humble willingness to serve when invited.
When the president of the Church passes away, the following events take place:
1. The First Presidency is automatically dissolved.
2. The two counselors in the First Presidency revert to their places of seniority in the Quorum of the Twelve Apostles. Seniority is determined by the date on which a person was ordained to the Twelve, not by age.
3. The Quorum of the Twelve Apostles, now numbering 14 and headed by the senior apostle, assumes Church leadership.
4. The senior apostle presides at a meeting of the Quorum of the Twelve to consider two alternative propositions:
i. Should the First Presidency be reorganized at this time?
ii. Should the Church continue to function with the Quorum of the Twelve presiding?
5. After discussion, a formal motion is made and accepted by the Quorum of the Twelve Apostles.
6. If a motion to reorganize the First Presidency is passed, the Quorum of the Twelve unanimously selects the new president of the Church. The new president chooses two counselors and the three of them become the new First Presidency. Throughout the history of the Church, the longest-serving apostle has always become the president of the Church when the First Presidency has been reorganized.
7. Following the reorganization of the First Presidency, the apostle who has served the second longest is sustained as the president of the Quorum of the Twelve. When the second-longest-serving apostle has also been called into the First Presidency as a counselor, the third-longest-serving apostle becomes acting president of the Twelve.
8. The president of the Quorum of the Twelve, along with the rest of the apostles, sets apart* the new president of the Church through a formal laying on of hands.
Since the Church was formally organized on 6 April 1830, there have been 16 presidents, including President Thomas S. Monson.
*After accepting a call to serve in a position, Church members are "set apart" to do so. This is done in accordance with the Biblical practice of laying on of hands. A priesthood leader places his hands upon the head of the person being set apart and offers a prayer, granting the individual the authority and capacity to perform the duties of the office and providing a personal blessing.