Abraham came 20 generations after Adam and was the first to conduct organized Kabbalah studies. He saw the wonders of human existence and asked questions of the Creator, and thus discovered the Upper Worlds.
Abraham passed the knowledge and the method he used to acquire the Upper Worlds to the generations following him. In this way, Kabbalah was transferred from teacher to students for many centuries. Each Kabbalist added his unique experience and personality to this body of accumulated knowledge.
Abraham lived in Mesopotamia (today’s Iraq) and, as all inhabitants, worshiped the sun, the moon, the stones, and the trees. But one day he began to wonder, “How was the world created?” “Why does everything ‘spin’ around us?” and “What does life mean?” Indeed, there must be some meaning to life, he thought, a beginning, end, cause and effect. There must be a force that sets everything in motion! Abraham asked himself those questions and, eventually, through the picture of our world, felt and saw the same as Adam did, that he lived in two worlds at once, the spiritual and the material.
And, yes, these are all the very same questions that have begun to bring Kabbalah to the fore in today’s society.
Like Kabbalists after him, Abraham wrote about his discoveries. His book, Sefer Yetzira ( The Book of Creation), is the next important text after HaMalaach Raziel. Unlike longer Kabbalah books, Sefer Yetzira has only several dozen pages.
Abraham’s purpose in writing his book was not to teach attainment of the Upper World, but only to mark out a few principal laws that he discovered about the spiritual world, like an outline.
Kabbalists consider it a difficult book to study correctly because it was written for people who lived thousands of years ago. In those days, souls of people were not as coarse as they are today. They could understand the text even though it is written very succinctly. Today we need a much more detailed text to be able to relate to it. This is why Baal HaSulam wrote his commentaries on The Book of Zohar and The Tree of Life.
When Abraham discovered spirituality, he immediately started disseminating his knowledge. This is why it is written that he would sit at his tent door and invite people in. There, he taught them what he had learned of the spiritual. Eventually, these students that Abraham would invite into his tent became the first study group in the history of Kabbalah.