Young said, "You see some classes of the human family that are black, uncouth, uncomely, disagreeable and low in their habits, wild, and seemingly deprived of nearly all the blessings of the intelligence that is generally bestowed upon mankind …. Cain slew his brother.
Cain might have been killed, and that would have put a termination to that line of human beings. This was not to be, and the Lord put a mark upon him, which is the flat nose and black skin. Trace mankind down to after the flood, and then another curse is pronounced upon the same race - that they should be the ‘servant of servants’
This too appears to be the teaching of Joseph Smith the organisation's founder. My conclusion is that not only were they false prophets but appear to be quite evil!