In the realm of faith, God is not a hypothesis derived from logical assumptions, but an immediate insight, self-evident as light. To rationalists He is something after which they seek in the darkness with the light of their reason. To men of faith He is the light.

Heschel made similar statements in earlier writings: The great insight is not attained when we ponder or infer the beyond from the here. In the realm of the ineffable, God is not a hypothesis derived from logical assumptions, but an immediate insight, self-evident as light. He is not something to be sought in the darkness with the light of reason. He is the light. | Man Is Not Alone: A Philosophy of Religion (1951)