I have questions about Mormons.?

I've seen Mormons write the most insane things on message boards. I even had one Mormon tell me that if he could explain why he believed what he did, I'd believe it too. They say they're Christians, but I don't see that at all. Why do they have such crazy theology, and why do they expect others to believe it? Why do they think Jesus and Satan are brothers and God is an alien with a human body? How can they possibly believe something that disgraced Freemason Joseph Smith wrote that was supposedly translated from gold plates hidden in his hat? I find them to be crazier than a sh*thouse rat. What can we do about this menace?