"Since Joseph Smith was younger than most of you and not nearly so experienced or well-educated as any of you at the time he copyrighted the Book of Mormon, it should not be too much to ask you to hand in by the end of the semester (which will give you more time than he had) a paper of, say, five to six hundred pages in length. Call it a sacred book if you will, and give it the form of a history. Tell of a community of wandering Jews in ancient times; have all sorts of characters in your story, and involve them in all sorts of public and private vicissitudes; give them names--hundreds of them--pretending that they are real Hebrew and Egyptian names of 
circa 600 b.c.; be lavish with cultural and technical details--manners and customs, arts and industries, political and religious institutions, rites, and traditions, include long and complicated military and economic histories; have your narrative cover a thousand years without any large gaps; keep a number of interrelated local histories going at once; feel free to introduce religious controversy and philosophical discussion, but always in a plausible setting; observe the appropriate literary conventions and explain the derivation and transmission of your varied historical materials...

A classic Mormon metaphor for the effects of immorality is presenting a clean glass of pure water to a volunteer.  "Would you drink this?", you say.  They respond, "Yes".  Then you put a hair in the water and ask the same question.  The response changes.