Belief in reincarnation seems to have originated in India and to have been introduced into hinduism from the tenets of the earlier inhabitants in about the 6th century b.c. According to this doctrine the souls of all living beings, plants, animals, men, and even gods, are subject to a perpetual cycle of rebirth (saṁsāra ). By the law of karma, the condition of a soul in this life is determined by its action in the past. A soul rises in the scale of being by performance of good deeds and descends by evil deeds, but in either case there is no finality. Even the gods must die when the universe is dissolved and be born again when a new creation begins. This doctrine must be judged, however, in the light of the corresponding beliefs that all creation is māyā, that is, ultimately unreal. The purpose of life is to realize the unreality of the world of becoming and to attain liberation (mokṣa ) in the world of absolute Being. This doctrine, common to Hinduism, buddhism, and jainism, gradually spread from India to the West.
"Reincarnation." New Catholic Encyclopedia. . Encyclopedia.com. (August 20, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/reincarnation
"Reincarnation." New Catholic Encyclopedia. . Retrieved August 20, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/reincarnation