You’ve no doubt seen this already at some point in your intertubes wanderings, but in case you haven’t, here’s a slightly older cartoon explanation of Mormonism. You can tell it’s older by the rotoscoped animation. And yes, this is a very close representation of their true beliefs.
My true belief is that Joseph Smith was a liar, a charlatan and a fraud, with a messiah complex the likes of which haven’t been seen since Jesus of Nazareth himself. That is, if Jesus even existed, which a number of secular historians strongly doubt… not that his historical veracity even matters, since if he existed, he was just a cult leader like Joseph Smith or David Koresh or Claude Vorilhon.