After leaving their bodies, they who have killed the Self go to the worlds of the Asuras, covered with blinding ignorance.
The idea of rising to bright regions as a reward for well-doers, and of falling into realms of darkness as a punishment for evil-doers is common to all great religions. But Vedanta claims that this condition of heaven and hell is only temporary; because our actions, being finite, can produce only a finite result.
What does it mean “to kill the Self?” How can the immortal Soul ever be destroyed? It cannot be destroyed, it can only be obscured. Those who hold themselves under the sway of ignorance, who serve the flesh and neglect the Atman or the real Self, are not able to perceive the effulgent and indestructible nature of their Soul; hence they fall into the realm where the Soul light does not shine. Here the Upanishad shows that the only hell is absence of knowledge. As long as man is overpowered by the darkness of ignorance, he is the slave of Nature and must accept whatever comes as the fruit of his thoughts and deeds. When he strays into the path of unreality, the Sages declare that he destroys himself; because he who clings to the perishable body and regards it as his true Self must experience death many
The Upanishads translated by Swami Paramananda
Text from: Project Gutenberg