The theory of the past life and of that our souls go through reincarnation has been existing for nearly 3,000 years. Who was I in a past life? Is there a life after my life? You can find arguments on these issues in the treatises of ancient Greece, India and the Celtic Druids. Millions of people believe that their spirit exists not only seven, eight or nine decades of life on Earth (as luck would have it), but also that we lived before and that we will live again.