A while back I came across a website dedicated to Einstein’s writings on God and religion. It’s fascinating to see how someone like Einstein approached topics like this. While he didn’t believe in a “personal God” he did believe in something. He was awestruck by the tremendously complex structure of Nature and the universe, and while he admitted that humans could only have an imperfect understanding of it all, it nevertheless gave him a “religious” feeling — stemming from deep humility, not mysticism. Here’s a good quote:
It seems to me that the idea of a personal God is an anthropomorphic concept which I cannot take seriously. I feel also not able to imagine some will or goal outside the human sphere. My views are near to those of Spinoza: admiration for the beauty of and belief in the logical simplicity of the order and harmony which we can grasp humbly and only imperfectly. I believe that we have to content ourselves with our imperfect knowledge and understanding and treat values and moral obligations as a purely human problem — the most important of all human problems.
The site has plenty of other quotes and writings by Einstein on this subject and similar ones, and it’s quite a good read.