The Book of Mormon offers so much that broadens our understandings of the doctrines of salvation. Without it, much of what is taught in other scriptures would not be nearly so plain and precious.
A doctrine serves no purpose in itself, but it is indispensable to have one if only to avoid being deceived by false doctrines.
The real breeders of discontent and alien doctrines of government and philosophies subversive of good citizenship are such as these who take the law into their own hands.
I would be cautious in embracing or rejecting doctrines. Had they been essential to our salvation, they would have been more explicitly declared in the Gospels, where we are so well taught the practice of every good word and work.