Ways in which Islam and Mormonism are similar:
• Both religions feature a prophet who received a new revelation supplementary to (and mostly replacing) Christianity, written down in a Holy Book.
• Both religions suffered an early split between one faction that got the charisma, and the other that got the prophet’s genealogy.
Ways in which Christianity and Judaism are dissimilar:
• Judaism is much older than Christianity, and comes from a time when each people would have its own gods. The Hebrews famously had only one God, Yahweh, with whom they had a special covenant. They might turn their back on Yahweh, but they were still members of the Hebrew nation. Christianity comes from a later date in human history, from an age of Hellenistic philosophy and a far-flung Roman Empire, and had a universal imperative: every single person on Earth was a potential Christian. As such there is nothing to separate the Christian from the non-Christian except belief, expressed through uttering the Creed. A lot of misunderstandings between Christians and Jews stem from this difference in kind.