Yes, I know it is actually 6 quotes--counting the one in the below image--but I find them all inspiring. For more quotes from Einstein, click here.
"Reality is merely an illusion, albeit a very persistent one."
"Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction."
"Peace cannot be kept by force. It can only be achieved by understanding."
"The most incomprehensible thing about the world is that it is comprehensible."
"My religion consists of a humble admiration of the illimitable superior spirit who reveals himself in the slight details we are able to perceive with our frail and feeble mind."
This image was found here.