Starting from the ruin of the Second Temple, the wisdom of Kabbalah was hidden until Isaac Luria Ashkenazi (The Ari) opened it to all humanity in the 16th century and let the world move toward correction.
The Ari belongs to the chain of the greatest Kabbalists throughout the generations. He is considered to be the father of the contemporary wisdom of Kabbalah. In his book The Tree of Life, the Ari, unlike the Kabbalists before him, reveals the structure and development of the universe and gives clear instructions on how we can ascend from our world, the lowest point in reality, to the highest, complete and eternal attainment of reality.
Behold that before the emanations were emanated and the creatures were created,
The Upper Simple Light had filled the whole existence.