I didn't say he believed in a personal god. He believed in a more abstract sort of god, one that reflected the mysteries that humans will never penetrate; he also said this concept defined his sense of being religious.

"A knowledge of the existence of something we cannot penetrate, of the manifestations of the profoundest reason and the most radiant beauty - it is this knowledge and this emotion that constitute the truly religious attitude; in this sense, and in this alone, I am a deeply religious man."

"I believe in Spinoza's God who reveals himself in the orderly harmony of what exists, not in a God who concerns himself with the fates and actions of human beings."