Mormonism is as different from Christianity as Islam is from Christianity.
Both Mormonism and Islam grew out of Christianity.
Both recognize the Bible as "corrupted scripture" that has been corrected by a later set of scriptures.
Both claim Jesus Christ as part of their religion.
Neither believe Jesus was divine in the Christian sense (meaning Jesus was God and that there is one and only one God that is unique--Mormons believe in multiple (as in millions of) gods, Muslims believe there is only one God, but Jesus wasn't God).
Both claim a prophet came after Jesus, and their prophet's words are the final say.
Both believe in a salvation by works.
The truth is, as far as their religious beliefs, Mormonism is closer to Islam than traditional Christianity.
I don't mean that to be insulting. It's just the truth.
It's also the reason Mormons are not Christians, any more than Muslims are Christians.
But Islam does have the GALL to proclaim that they ARE Christian; and the ONLY true ones at THAT!