Marshall Applewhite and Bonnie Nettles founded the religious group Heaven's Gate in the 1970s. They believed that they were the two witnesses from the Book of Revelation and that they had to prepare their followers to leave Earth on a spaceship hidden behind the Hale-Bopp comet. The group practiced strict rules and rituals aimed at overcoming human tendencies like sexuality. After Nettles' death in 1985, Applewhite came to believe that the only way to reach the "Next Level" was by shedding one's human body through suicide. In 1997, he led 39 followers in a mass suicide so their souls could board the spaceship before it passed Earth. The group's website is still online with their final messages