The clearest of those here is Einstein's critique of religion as not sophisticated enough to render the universe as Einstein understood it. This is something he said, or at least hinted at, many times, such as when he wrote to a U.S. Navy ensign that he considered a father-figure-like understanding of God to be a consequence of "childish analogies." Religion, Einstein believed, made a caricature of God.
That's not, however, because Einstein rejected the notion of God, but because he took the idea of God very seriously, elevating it above a religious conception to a mathematical one. To Einstein, the elegance of the physics guiding the universe were God's handiwork, the mark not of a humanlike being that maintains control over the world, but of a divine beauty in nature's laws. As Walter Issacson wrote in his biography, following a religious phase in childhood, Einstein retained "a profound reverence for the harmony and beauty of what he called the mind of God as it was expressed in the creation of the universe and its laws."
Einstein's God -- deeply shaped by the ideas of Baruch Spinoza -- was a "superior reasoning power, which is revealed in the incomprehensible universe," he wrote. His religion followed from there. As Isaacson tells it:
One evening in Berlin, Einstein and his wife were at a dinner party when a guest expressed a belief in astrology. Einstein ridiculed the notion as pure superstition. Another guest stepped in and similarly disparaged religion. Belief in God, he insisted, was likewise a superstition.
At this point the host tried to silence him by invoking the fact that even Einstein harbored religious beliefs.
"It isn't possible!" the skeptical guest said, turning to Einstein to ask if he was, in fact, religious.
"Yes, you can call it that," Einstein replied calmly. "Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible laws and connections, 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 fact, religious."
In a 1930 essay, Einstein expressed this another way: "To sense that behind anything that can be experienced there is something that our minds cannot grasp, whose beauty and sublimity reaches us only indirectly: this is religiousness. In this sense, and in this sense only, I am a devoutly religious man."
Prayer would have little influence over such a God and have no role in Einstein's personal religion. "Scientific research is based on the idea that everything that takes place is determined by laws of nature, and this holds for the actions of people," he told a sixth-grade girl. "For this reason, a scientist will hardly be inclined to believe that events could be influenced by a prayer, i.e. by a wish addressed to a supernatural Being."