According to the Hindu Puranas, there are fourteen worlds in the universe - the seven upper and the seven lower. The seven upper worlds are Bhuh, Bhavah, Swah, Mahah, Janah. Tapah, and Satyam; and the seven nether worlds are Atala, Vitala, Sutala, Rasatala, Talatala, Mahatala, and Patala. The region known as Bhuh is the earth where we dwell, while Swah is the celestial world to which people repair after death to enjoy the reward of their righteous actions on earth. Bhuvah is the region between the two. Janah, Tapah, and Satyam constitute Brahmaloka, or the highest heaven, where fortunate souls repair after death and enjoy spiritual communion with the personal God, and at the end of the cycle attain liberation, though a few return to earth again. The world of Mahah is located between Brahmaloka and Bhuh, Bhuuah, and Swah. Patala, the lowest of the seven nether worlds, is the realm where wicked souls sojourn after death and reap the results of their unrighteous actions on earth. Thus, from the viewpoint of Hinduism, heaven and hell are merely different worlds, bound by time, space, and causality. According to Hinduism, desires are responsible for a person's embodiment. Some of these desires can best be fulfilled in a human body, and some in an animal or a celestial body. Accordingly, a soul assumes a body determined by its unfulfilled desires and the results of its past actions. An animal or a celestial body is for reaping the results of past karma, not for performing actions to acquire a new body. Performance of karma to effect any change of life is possible only in a human body, because only human beings do good or evil consciously. Human birth is therefore a great privilege, for in a human body alone can one attain the supreme goal of life. Thus, in search of eternal happiness and immortality, the apparent soul is born again and again in different bodies, only to discover in the end that immortality can never be attained through fulfillment of desires. The soul then practices discrimination between the real and the unreal, attains desirelessness, and finally realizes its immortal nature. Affirming this fact, the Katha Upanishad says: "When all the desires that dwell in the heart fall away, then the mortal becomes immortal and here attains Brahman."
Death, according to Hinduism, is a series of changes through which an individual passes. The Brihadaranyaka Upanishad describes thus the passing of a soul:
When the soul departs from the body, the life-breath follows: when the life-breath departs, all the organs follow. Then the soul becomes endowed with particularized consciousness and goes to the body which is related to that consciousness. It is followed by its knowledge, works, and past experience. Just as a leech supported on a straw goes to the end of it, takes hold of another support, and contracts itself, so does the self throw this body away and make it unconscious, take hold of another support, and contract itself. Just as a goldsmith takes a small quantity of gold and fashions another - a newer and better - form, so does the soul throw this body away, or make it unconscious, and make another - a new and better - form suited to the Manes, or the celestial minstrels, or the gods, or Virat, or Hiranyagarbha, or other beings. . As it does and acts, so it becomes; by doing good it becomes good, and by doing evil it becomes evil - it becomes virtuous through good acts and vicious through evil acts.
Hinduism speaks of the four courses that men follow after death. The first, called devayana, way of the gods, is followed by spiritually advanced souls who lead an extremely pure life, devoting themselves to wholehearted meditation on Brahman, but who have not succeeded in attaining complete Self-knowledge before death. They repair to Brahmaloka, the highest heaven, and from there in due course attain liberation. The description of this path in the Chhandogya Upanishad is as follows:
Now, such a one-whether his after-death rites are performed or not-goes to light, from light to day, from day to the bright half of the month, from the bright half of the month to the six months during which the sun rises northward, from the months to the year, from the year to the sun, from the sun to the moon, from the moon to the lightning. There he meets a person who is not a human being. This person carries the soul to Brahman. This is the divine path, the path of Brahman. Those proceeding by this path do not return to the whirl of humanity.
The second course, known as pitriyana, way of the fathers, is followed by ritualists and philanthropists who have cherished a desire for the results of their charity, austerity, vows, and worship. Following this path, they repair to Chandraloka, the lunar sphere, and after enjoying immense happiness there as a reward for their good actions, they return again to earth since they still have earthly desires. The third course, which leads to hell, is followed by those who led an impure life, performing actions forbidden by the scriptures. They are born in sub-human species. After expiating their evil actions, they are again reborn on earth in human bodies. The fourth course is for those who are extremely vile in their thoughts and actions. They are reborn again and again as insignificant creatures such as mosquitoes and fleas. Eventually, after the expiation of their evil actions, they too return to human bodies on earth. When a soul assumes a human body, it takes up the thread of spiritual evolution of its previous human birth and continues to evolve toward Self-knowledge. According to Hinduism, all souls will ultimately attain Self-knowledge. The four courses do not apply to those souls who attain Self-knowledge before or at the time of death. For these souls there is no going to any realm. Upon their death, their souls become absorbed in Brahman, and the elements of their body-mind complex return to their original source.
From the point of view of Hinduism, dying may be compared to falling asleep and after-death experiences to dreams. The thoughts and actions of the waking state determine the nature of our dreams. Similarly, after death the soul experiences the results of the thoughts it entertained and the actions it performed during its life on earth. After-death experiences are real to the soul, just as a dream is real to the dreamer, and may continue for ages. Then, when the soul wakes up after this sleep, it finds itself reborn as a human being. According to the Hindu scriptures, some souls after death also may be born as human beings without going through the experiences of heaven or hell. There is no real break in the spiritual evolution of the soul toward Self-knowledge. Even the soul's lapse into sub-human birth from human life is a mere detour. A dying man's next life is determined by his last thought in the present life. The Bhagavad Gita says: "For whatever objects a man thinks of at the final moment, when he leaves the body - that alone does he attain, O son of Kunti, being ever absorbed in the thought thereof." And the last thought of the dying person inevitably reflects his inmost desire. These different courses after death have been described to warn people against neglecting the path of Self-knowledge, which alone can confer immortality and eternal peace and happiness.