I read the book of Jacob through the Book of Mormon.
The book of Jacob is basically segmented into three parts (although 7 chapters).
The first is the exhoration against sin, the second a long quote from a prophet named Zenos, and a final section in which Sherem is introduced and killed.
In the first section, the main sins are greed and lust; however, lust is the one most focused upon. The reasons behind why lust is bad are not described. We see Jacob describe the anger and dislike that God has toward those who are polygamous or otherwise disposed toward numerous partners, and this anger is poised as more than just a cause of fear--it is a cause of denigration. For, as Jacob notes, even the Lamanites have monogamous relationships, wherein the husband and wife love each other and their children. This section is steeped in racism of the lowest order, with the curse of a darker skin tone being a sign literally of sinfulness, which is juxtaposed to the white Nephites who are nevertheless evil, not as a result of their forefathers, but as a result of themselves. The whiteness of the Lamanites will be shown in the final judgment, but the Nephites, if they don't change, will be black!
The Zenos section, I was happily surprised to note, was not plagiarized from the Hebrew Bible, but was a creation of the mind of Joseph Smith himself. It details a story of a lord who owns a vineyard. He sees a tree near death, grafts wild branches onto it, and takes branches from the tamed tree and grafts them and plants them around his vineyard; afterwards, the trees give good fruits, but soon become totally corrupt, and the mistake the lord makes becomes evident; thus, he desires to save his trees, and the method of doing this, as proposed by his servant (which, I suppose, is the Christ), is to graft on the original branches from other trees, pruning and destroying the bad things and keeping the good things. Wonder of wonder, this works, and we hear that our friend the lord shall collect numerous fruit for the winter and one day his vineyard shall burn.
Our narrator resumes by stating that this is the selfsame story of the Jewish people and what shall happen to them. At this point, we also get a discussion on a false prophet among the Nephites. Sherem doesn't believe in the Christ and decides to talk about it. He is a good talker, probably influenced by the devil, and begins to convince people, but he chooses to try his worst enemy (Jacob): a choice which results in him being cursed by Jacob (although unwillingly) to be smited by God as proof of the Christ, which smiting occurs, and the final thing we hear of Mr. Sherem is that he repents of all his beliefs, fears God's retribution in death, and his immediate death after speaking. There is no point in me saying that the fate of Sherem is unjust. If he was possessed of the devil, he had no agency, and his actions were not his; if he was not, and he just needed further proof, we already know from the other books the many wonders God enacts upon the people, so that, I mean, why not do it again?
Most of what I care about in this book comes from the story elements (like the pretty little folkish tale of Sherem or the tale of the vineyard lord), for the theology lacks lustre and deepness, and the main goal of the work (to show that the people of Nephi knew of Christ, etc., etc.) is not only obviously bunk and a scam, but is rather an odd thing to drone on about when we hear our friend Jacob, again and again, relate that he has limited space. Say it once and get onto something else!!