Einstein liked Mach, Spinoza, Hume, Cervantes, Goethe, Dostoevsky and Blavatsky. Here is what he said about his belief:

“I believe in Spinoza’s God, who reveals himself in the harmony of all that exists, not in a God who concerns himself with the fate and the doings of mankind.”

Edit: There are rumors that Einstein used drugs, but they are largely unsubstantiated. On the other hand, other famous modern thinkers did.