Something that 1.6 million Muslims would deny to their last breath:
"The religion [Muhammad] founded began as a classic millennial cult comprising Jews, Christians and Arabs driven by an apocalyptic belief in the end of the world, with Jerusalem as its original focus. The purely Arabian provenance attributed to Islam and its prophet were later inventions by pious scholars who tried to curb the power of the caliphs by using the memory of Muhammad, with its iconic moral authority. The empires of the caliphs are long gone, but the sunna of the prophet—his custom and example—endures."
From "A Startling Thesis on Islam's Origins."
So "Heaven's Gate" and Islam have a shared point of origin. As did Muhammad and Charles Manson.