Kabbalah is considered one of the world’s oldest bodies of spiritual wisdom. This esoteric school of thought originated in Judaism, with contemporary Christian and New Age followers. Abraham the Patriarch is recognised as the first Kabbalist and author of the Sepher Yetzirah, 'The Book of Formation.' Other foundational texts include the Zohar and writings of the 16th century kabbalist Rav Isaac Luria (the Ari). The word Kabbalah means 'to receive' and it is the study of how to receive fulfillment. Its teachings attempt to explain the relationship between an eternal and mysterious infinity with the mortal and finite universe.