"Stanford Encyclopedia of Philosophy has an extensive article."

“I cannot get from the nature of the proposition to the individual logical operations!!! That is, I cannot bring out how far the proposition is the picture of the situation. I am almost inclined to give up all my efforts.”

“It is true: Man is the microcosm: I am my world.”

“The World and Life are one. Physiological life is of course not "Life". And neither is psychological life. Life is the world. Ethics does not treat of the world. Ethics must be a condition of the world, like logic. Ethics and Aesthetics are one.”

“There are two godheads: the world and my independent I. I am either happy or unhappy, that is all. It can be said: good or evil do not exist. A man who is happy must have no fear. Not even in the face of death. Only a man who lives not in time but in the present is happy.”

“To believe in a God means to understand the question about the meaning of life. To believe in a God means to see that the facts of the world are not the end of the matter. To believe in God means to see that life has a meaning.”

“What do I know about God and the purpose of life? I know that this world exists. That I am placed in it like my eye in its visual field. That something about it is problematic, which we call its meaning. This meaning does not lie in it but outside of it. That life is the world. That my will penetrates the world. That my will is good or evil. Therefore that good and evil are somehow connected with the meaning of the world. The meaning of life, i.e. the meaning of the world, we can call God. And connect with this the comparison of God to a father. To pray is to think about the meaning of life.”