Throughout the course of her career Lillian Roth (1910 - 1980) had lived the high life, as well as the low. It was during one of her darker moments, while she sat pining in the depths of her anguish, that a well-wisher approached her with a unique line of reasoning that was so pure in its simplicity it immediately lead her to realize that God does indeed exist:
"Lillian, you think of God. Why? Because God exists. If He did not exist, you could not have thought of Him."
"You cannot imagine anything completely non-existent. No matter what you think of, however bizarre or fantastic: a five-legged man, a mind composed of mist and echo, an impossible creature from another planet - you discover that part of your concept is based on reality. So it is with God: for if any part of the concept of God is real, then God Himself is real."
Two Books from Amazon: I'll Cry Tomorrow by Lillian Roth.
(In 1955 MGM made this book into movie of the same name; it starred Susan Hayworth)