The Twelve Apostles are chosen as special witnesses of Christ to all the world. The quorum is the second-highest governing body of the Church. It becomes the presiding body of the Church in the event of the death of the prophet, until a new President of the Church is chosen and ordained.
“Calling an Apostle of the Lord,” ChurchofJesusChrist.org
“Meet Today’s Prophets and Apostles,” ChurchofJesusChrist.org
“President Nelson Reflects on Being an Apostle of the Lord,” Church News
“Apostles,” Lesson Helps for Teaching Children
“Special Witness,” Lesson Helps for Teaching Children