Alma explained the importance of the sacred American records and commanded his son Helaman to take charge of them:
Now ye may suppose that this is foolishness in me; but behold I say unto you, that by small and simple things are great things brought to pass; and small means in many instances doth confound the wise.
And the Lord God doth work by means to bring about his great and eternal purposes; and by very small means the Lord doth confound the wise and bringeth about the salvation of many souls.
Through simple means the Lord confounds the wise and brings to pass great things. The Book of Mormon is one small book among millions, but will end up changing the course of the world.
Source: Alma 37:6-7; The Book of Mormon: Another Testament of Jesus Christ