I have read the Book of Mormon and to say the least, it is a bit strange. Now I am assuming you're an Evangelical Christian. Evangelicals make a strong point in saying that Mormons (and jehovah's witnesses) are not Christian even though Jesus is included in their belief system & theology. On this point, the evangelicals are right. They are not Christians in the sense that most Christians define Jesus, the Trinity etc. Now, this is where I ask a question. Evangelicals are also quick to call Mormonism a cult. Now how do thy mean that? In the wacky sense, that they'll kidnap you, lock you in a basement and brainwash you till your mid is goo? Or in the more benign sense based on the that the belief system is not revealed from God, but rather a man made concoction?
Read Walter Martin's excellent book "Kingdom of the Cults". In it he defines a cult as a religion that makes a claim of Christianity while denying one or more of the basic tenets of Christianity.
I think they would be a cult, but in this case it is a cult of some of the nicest people.
So being they don't hurt other people and are often nice, this is one cult I have no problem with.
Definition of a cult, see bottom of link:
http://www.ex-cult.org/
I don't believe Jesus is included in JW's system - certainly not as the Son of God
Mormonism is as related to Christianity as Islam -- both do not subscribe to the idea of a Trinity: both consider Jesus to not be of the same substance as God. The difference is that the Muslims take a more Arian view while the Mormons seem akin to Gnosticism.
American evangelicals tend to use the word "cult" for any religion (but especially for ones that call themselves Christian) that have so deviated from basic orthodox Christian doctrines (things Protestants, Catholics, and Orthodox have always agreed on....) like the trinity, the person of Christ (fully human, fully God), the resurrection, etc. that the word "Christian" no longer accurately defines them. Though some cults are really strange and wacky (especially California based ones...) other older ones, like Mormonism and say JW's are externally not that wacky, just very un-biblical--in the judgement of Christians. The differences between denominations pale (Lutheran, Baptist, Presbyterian, Methodist, etc) compared to the differences between all Christian groups and claimed "Christian" cults.
Groups that cease to claim the name Christian (like Unitarians, for example) generally aren't called cults....as there is no false advertising. However some small newer groups...even if they don't claim the name "Christian" are called cults...generally if they are strange and controlling. A strong leader, and strong control over members usually marks a cult, in this secondary sense.
The same anger is focussed on theologically liberal "Christians" (though usually not called cults...just apostate or heretical) who have rejected those same kind of basic orthodox doctrines all Christians have believed---yet still want to claim the name "Christian."
I would have far less trouble with (and more respect for...though I'd disagree as strongly) if folks like the gay Episcopal Bishop Robinson would face up to the fact that they are simply no longer Christians....and while they have every right to believe whatever they want, they shouldn't purger themselves pretending what they simply are not.
The word "Christian" dates back to Antioch and the 1st Century persecuted Church. Naturally we followers of Jesus guard that word jealously.
Jesus Christ is my Lord and Savior. I'm a Mormon.