Belief in reincarnation, literally "to be made flesh again", is an ancient phenomenon. This doctrine is a core of the majority of different Indian and Buddhist religious traditions. The idea was also explored by ancient Greek philosophers and Persian religious teachers already over 2,000 years ago. But what about the Judaism? Many Jews might be surprised to realize, that reincarnation - the "revolving" of souls through a succession of lives, or "gilgulim" - is an integral part of general Jewish belief today. But how has it happened?
It took a long time until this idea has managed to penetrate and get deeply rooted in the Jewish thought. We have nothing like reincarnation mentioned in the Bible. Moreover, out of 24 Jewish Bible books, in 23 there is nothing said even about an after-life. The Ancient Jewish thought was highly deterministic, and the souls of the dead were simply expected to descend the World of Dead, Sheol, which was very similar to Hades of the Ancient Greeks. It was no way back, no after-life and no resurrection, no reward of punishment after the death. The God' rewords for rightfulness and punishments for sins were all confined to the person' life time (like it was the best described in the Book of Job).
The first time the after-life and the resurrection of the dead are mentioned in the Book of Daniel, written "only" 2,200 years ago. By that time and on, the general belief in after-life and resurrection of the dead has become the core of the Jewish Religion. And still, the idea of the reincarnation is never mentioned in an Oral tradition – Mishna and Talmud. This might be surprising as it already became a part of many religions in the countries of Jewish Diaspora.
Moreover, very soon after the Babylonian Talmud was concluded, already in the 8 Century CE, the question of the reincarnation became a subject of the hot discussion among the Jewish religious leaders. The earliest possibly outspoken believer in Reincarnation among the Jews was Anan ben David who was one of the leaders of the Babylonian Jews and is considered as a founder of the religious Jewish group called Karaite, which still exists.
But the major change had to wait another 400 years. In the late 12th Century, in the South France, in the area called Languedoc, a book called "Sefer Ha-Bahir" (Book of Brightness) appeared for the first time. This was the first book of the mystical teachings of Kabbalah, and a part of it was, for the first time, dedicated to the Reincarnation.
Was it just a coincidence that Languedoc was a center of a powerful religious movement called the Cathars ("the pure ones")? Cathars origins are something of a mystery though there is reason to believe their ideas came from Persia or the Byzantine Empire, by way of the Balkans and Northern Italy. Like the Jews and the Christians, Cathars believed in two principles - a good god and his evil adversary. But, opposite to the Christians and the Jews, it was the Evil who had created the material world, full of sin. The human soul must purify itself from the sin, and to ensure that the God has created the Reincarnation. The soul moves from one body to another (reincarnates) purifying itself at each stage.
In the Languedoc, known at the time for its high culture, tolerance and liberalism, the Cathar religion took root and gained more and more adherents and by the early thirteenth century Catharism was probably the majority religion in the area. The Cathars had very good relations with the local Jews, and their exchange of thoughts is far from being surprising. And that was also a century when one of the greatest Jewish thinkers Ramban ("Nachmanides") had already insisted that already in Biblical times the sons of Jacob were aware of the secret of reincarnation.
And at the same time in the neighboring Spain another book was published by a certain Rabbi Moshe de Leon – the Book of Zohar ("The Splendor"). De Leon ascribed the work to the Rabbi Shimon Bar Yochai ("Rashbi")