Carl Sagan did not consider himself an atheist.
Sagan wrote frequently about religion and the relationship between religion and science, expressing his skepticism about the conventional conceptualization of God as a sapient being. For example:
"Some people think God is an outsized, light-skinned male with a long white beard, sitting on a throne somewhere up there in the sky, busily tallying the fall of every sparrow. Others—for example Baruch Spinoza and Albert Einstein—considered God to be essentially the sum total of the physical laws which describe the universe. I do not know of any compelling evidence for anthropomorphic patriarchs controlling human destiny from some hidden celestial vantage point, but it would be madness to deny the existence of physical laws
Yes, he also said "An atheist has to know a lot more than I know. An atheist is someone who knows there is no god. By some definitions atheism is very stupid."
What was your point again?
Are you unsure if God exists? Do you wonder how the universe was created?