2 Nephi 4:15-19 Within one's capacity to have a sober mind, there is the strength of legions and the power of God. The glories of God when experienced in a pureness of heart are rapturous beyond description. Yet without a sober outlook and the ability to frequently remember one's own weaknesses, such powerful, divine manifestations are lost as quickly as they come. A sober mind and a sincere heart then make us capable of doing the Lord's work and prepares us as human beings to handle the extremely powerful manifestations of the Holy Ghost, to work with His influence, and to avoid the cycle of pride common to man. This explains the look that I have seen in the eyes of several bishops I've work with over the years. Where I would have expected to have seen great excitement or rejoicing, instead the response was calm yet appreciative. It is the mastery of themselves and knowing who's work they are about that invokes a sober response.
A personal study of the Book of Mormon by Brent Leavitt,
a member of the Church of Jesus Christ of Latter-day Saints.