The answer to the question -- which best describes a major belief of Hinduism -- is "reincarnation." Reincarnation is central to the practice of Hinduism. According to this exceedingly polytheistic religion ("monotheism" is the exact opposite of Hinduism), the soul is reincarnated repeatedly until it reaches the stage of perfection. That stage of perfection is defined as the attainment of a relationship with God. As stated in one of the central texts of Hinduism, the Bhagavad Gita:
"As man casts of his worn-out clothes and takes on other new ones, so does the embodied soul cast off his worn-out bodies and enters others new." (2:22)
Concepts of reincarnation have their origins in the ancient texts of Hinduism, and contemporary believers in reincarnation cite these texts as a source of wisdom. Hinduism, of course, is the main religion in India, a huge country of well-over one billion people the population of which is expected to overtake China over the next twenty years.