The king of the Lamanites promised the Lord, "I will give away all my sins to know thee." (Alma 22:18.) As is evident in his subsequent life, the king was promising the Lord that he would repent of all of his sins, forsake them, and start keeping the commandments of God. Some students of the Book of Mormon have wondered concerning the miraculous and almost instantaneous conversions of King Lamoni (Alma 18:40-43 and 19:1-36) and the king of the Lamanites (Alma 22:15-23). However, it is possible for people to be immediately converted to the gospel if they are sincere in wanting to repent of their sins and in learning the truth. Concerning how long it takes a person to repent, Heber C. Kimball said:
On the day of Pentecost, when Peter proclaimed the Gospel, about 3,000 souls were added to the Church that day. How long did it take them to repent? No longer than they were willing to believe, and put away their sins, with a determination to forsake them, and not sin again. (Journal of Discourses, 1:36.)