Having seen, in his vision, the administration of our Lord and his disciples, Nephi now sees that the result of their work was that righteousness prevailed among the people for a period of three generations, but that in the fourth generation, i.e. in the fourth century after the manifestation of our Lord, unbelief and iniquity again predominated to such an extent that war, pestilence, famine and other calamities swept the land, until the Nephites became extinct. (Morm. 6)