Old religions like Hinduism, Buddhism, and other eastern religious beliefs all include the concept of spiritual growth and also reincarnation. In fact, it is one of those unsolved mysteries in science how some individuals are capable of nearly superhuman feats merely by belonging to such a religion even though they might not be active participants or adherents to the faith. These people often say that all human beings are capable of performing the same feat and that there is nothing special about their own mind or body.
The concepts of the balance of karma and spiritual growth are common across the aforementioned religions and even people who do not follow the doctrines but accept the spiritual aspects report an improvement. This is significant because it seems to imply that as an individual progresses with spiritual growth and improvement of karma, then the material world seems to automatically align itself with the spiritual trends leading to more peace and tranquility within and without.
Reincarnation philosophies believe that every one has a higher self that is truly enlightened and that our repeated lives are a means to seek the true balance in our Karma and become enlightened in spirit. The precise terms and details behind this process change with every religion yet the core issue remains the same. Another common point is that reincarnation is necessary because enlightenment is not a quick process and human life span is too short to achieve it in one attempt. One must go through several cycles, each acting as a further refinement on previous development, until we reach our higher self and enlightenment dawns.
There are many tales of Indian saints who have performed recorded feats that have earned them the superhuman status that their followers believe they deserve. Devraha Baba was one such saint who lived in the city of Mathura. The story goes that he lived for more than seven centuries and was known as the "Ageless Yogi" to those who knew him. He did this by conquering his hunger and also the time of death. Another yogi from India, Subbayah Pullavar, has been recorded to levitate for a full five minutes in the presence of a hundred and fifty witnesses. Probably the most widely recognized of all such saints is Sri Sathya Sai Baba who was named "Man of Miracle" and the title is well deserved if there is any merit to the tales associated with him.
Individuals like these were spiritual in nature and had dedicated several years to their spiritual growth. If one follows their example that it would seem that death itself is something that may be conquered through proper spiritual development. While these beliefs are quite ancient, it is clear that the early masters were successful in establishing a link between our spirit or karma and the cycle of reincarnation. It is assumed that once an individual has achieved a certain level of spiritual growth then their abilities are naturally enhanced and they appear to be superhuman to those who have yet to attain those levels.