When asked by an astounded atheist, if he were in fact deeply religious, Einstein replied:
Yes, you can call it that. Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable. Veneration for this force beyond anything that we can comprehend is my religion. To that extent I am, in point of fact, religious.
— H. G. Kessler, The Diary of a Cosmopolitan, (London: Weidenfeld and Nicolson, 1971), p.157; quoted in Einstein and Religion by Max Jammer (Princeton University Press, 1999) pp. 39-40.