The Bodhisatta was once a god in heaven. His name was Dhamma (“Right”), and on holy days after the evening meal he rode around the world with a multitude of nymphs in his celestial chariot telling people they would be destined for heaven if they did good deeds like taking care of their parents and avoided evil such as killing living creatures. While the Bodhisatta promoted righteousness, another god, Adhamma (“Wrong”), went out promoting killing and other evildoing.
One day their chariots met in the air and the Bodhisatta, proclaiming his virtue, told Adhamma to move aside and give him the right of way. When Adhamma refused, he plunged head-first toward the earth, which opened up to send him to the deepest hell.
In the Lifetime of the Buddha
Adhamma was an earlier birth of Devadatta, a disciple of the Buddha who became his nemesis and tried to kill him three times. One time the Buddha heard some of his disciples discussing how Devadatta’s wickedness had caused the earth to swallow him up and he told them this story so they knew Devadatta had also been cast to hell for challenging his moral authority in the past.
The followers of both the Bodhisatta and Adhamma were earlier births of the followers of the Buddha and Devadatta.