When Brigham Young became the second president of the Church after Joseph Smith was killed, some people did not think he was the rightful president. When Brigham Young led most of the Mormons to Utah, these people stayed in Illinois. They believed that Joseph Smith's son should be the next president. Today, this church is called the Community of Christ. It is the second largest church to call themselves Mormons. They have more than 250,000 people in their church. Other Mormons teach very different lessons that the Community of Christ do not.