A New Earth. Eckhart Tolle.

The answer is simple, once you realize what the ego is and how it works. When forms that you had identified with, that gave you your sense of self, collapse or are taken away, it can lead to a collapse of the ego, since ego is identification with form. When there is nothing to identify with anymore, who are you? When forms around you die or death approaches, your sense of Beingness, of I Am, is freed from its entanglement with form: Spirit is released from its imprisonment in matter. You realize your essential identity as formless, as an all-pervasive Presence, of Being prior to all forms, all identifications. You realize your true identity as consciousness itself, rather than what consciousness had identified with. That’s the peace of God. The ultimate truth of who you are is not I am this or I am that, but I Am. Tolle, Eckhart. A New Earth (pp. 56-57). Penguin Books Ltd. Kindle Edition.