Alma the younger (who was not a young man) and the sons of Mosiah rebel against their fathers and against the church. They go around Zarahemla teaching people not to believe in Christ and not to believe the words of Alma the High Priest. They are having a lot of success leading people away from the church. God hears the prayers of the people of the church and the prayers of Alma and an angel comes and speaks with a voice of thunder that shakes the earth! He commands Alma to stop. Alma cannot speak or move his arms or legs. His father rejoices and knows this is an answer to his prayers! He gathers the people of the church and they and the priest fast and pray for 3 days for God to open Alma's mouth. Alma arises after 3 days and teaches the people about Christ. He and the sons of Mosiah spend the rest of their lives as missionaries "zealously" striving to repair the damage they have done to the church. They are instruments in the hands of God bringing many to the church! They do not want any to feel the dark, despair, the burning that Alma felt before he felt God's forgiveness and redeeming love.
