Mormonism is just weird, to be honest.
It all started when the
con artist prophet Joseph Smith made up a story about was visited by an angel, who told him that he would be the one to restore the fallen church. The angel led him to a set of golden plates buried in upstate New York, which Smith translated using bullshit mystical powers, and produced a narrative called the Book of Mormon.
It and other documents describe God as being an ascended being from the star Kolob, who physically produced humans as "spirit children" who could one day create and rule their own little universes if they were good enough Mormons in life. The narrative centers around the Nephites and Lamanites, refugees from the Babylonian invasion of Israel who fled across two oceans and settled in the Americas. Jesus apparently visited them after His resurrection. The good Nephites and the evil Lamanites apparently fought each other often, culminating in the Lamanites destroying the Nephites and becoming the ancestors of today's Native Americans. Of course, the Lamanites were cursed with having a "skin of blackness" at one point, explaining why Native Americans have brown skin and why they should be subjugated under whites.
As the above post states, Mormons do not accept any church councils as valid. According to Joseph Smith, the entire church fell away from God around 100 AD and has ben living in darkness since. The Mormon church is considered to be God's restoration of the original faith, and the only True Church in existence.
Moromns do have a secretive, cult-like aspect to them, I'll admit. Many of their rituals are performed in temples where non-Mormons are not allowed to enter, and are discussed little with outsiders. I lived in Utah during the summer of 2009 when I was working as a docent at Dinosaur National Monument, and it was different from most other places I'd done similar work in. Everything looked similar to typical clean, small-town life, but there were a lot of subtle things that just seemed "off" or wrong about the place that are hard to explain.