Śaṅkara

The great systematiser of Advaita — non-dual Vedānta. His position, argued through vast commentaries in a life traditionally said to have lasted thirty-two years: there is one reality without a second; the self you are is that reality; and the apparent world of separate things is real enough to stub your toe on and not ultimately real, which is what māyā names.

The purest form of the answer this door ends at, and the one that most sharply parts from the Tree. The Kabbalah will not say the soul is God. It will say the soul is a lamp of God, a portion from above, a spark — every one of those images keeping a distinction Advaita dissolves on principle.