Jacob, The Book of Mormon

Jacob was one of two younger brothers of Nephi. He was born in the wilderness after the family's departure from Jerusalem. This must have been a difficult time for them because they were obliged to be as unobtrusive as possible. The scripture, in fact, mentions no contact at all, either in the wilderness or after the crossing of the ocean, with any other people, Israelite or Gentile.
This means that, as far as we know, Jacob spent his life exclusively with members of his extended family, who may never have numbered more than a few hundred during his lifetime. It is easy to see how Nephi would be the greatest influence on his thinking, and would have presented the main example of a life spent in serving the Lord through laboring on behalf of those around him.
Jacob's teachings are similar to Nephi's in one other way. Nephi made a point of speaking and writing "plainly", only rarely speaking in metaphors or teaching symbolically in the fashion of Old Testament prophets. When he did use figures of speech, he was always quick to include an explanation of the lesson's meaning to his audience. What's more, he saw this type of instruction as the model his successors would use thereafter.
Jacob's teachings followed this pattern. On one occasion  he apologized for having to speak against sins he had noticed creeping into the community instead of speaking of love and eternal happiness. He had little use in speaking of  "gray" areas of conduct, but drew clear lines between righteous and lives diminished by pride and adultery, two sins he specifically rebuked.
He also spoke about things that might seem unusual for a person whose own education had been informal. He recognized the value of education, but warned that it may cause people to be subject to pride. Riches, he said, should not be sought for the purpose of mere accumulation, but for the good of those with less. His record, like other Book of Mormon prophets, carried an unmistakable Christian message even though his own life preceded Jesus' ministry by more than five hundred years.