Hong Xiuquan (1814–1864) called himself the Heavenly King. He had a vision he was the younger brother of Jesus Christ. He claimed he was sent to Earth to destroy Confucianism and the ruling Qing Dynasty. He achieved neither, but he did kill a lot of people.
At age 22, Hong took the imperial exams, and failed. But then he ran into a Christian missionary who taught him about Jesus.
A year later, Hong failed the imperial exams again and had a nervous breakdown. After that, he had a vision that he was the son of God. He felt that it was his heavenly mission to destroy the Qing Dynasty and set up his own—since he was, after all, the son of God and stuff.
Tens of thousands of people believed him, for some reason.
He used this power to launch the Taiping Rebellion, and establish his own mini-dynasty called the Taiping Tianguo (Heaven Kingdom of Eternal Peace). It lasted an “eternity” of 13 years. Over the course of countless battles, and estimated 20 million people were killed.
Just as the China’s Qing army was about to finally crush Hong Xiuquan in 1864, he committed suicide. But apparently that was not enough. The Qing soldiers exhumed his body, then beheaded and burned it, just to be extra sure he was really, really dead.
To learn more: check out Jonathan Spence’s “God’s Chinese Son.”