"I am against religion because it teaches us to be satisfied with not understanding the world."
Richard Dawkins
Even though I usually feel his criticisms paint "Religion" too simplistically, the most inspirational thing I have ever heard is from Dawkins, on this video:
Dawkins' "God Delusion" was the voice of reason that spoke to me finally in accepting the fact that I am atheist. Since I've read many of his books and watched many of his debates. It was his explanations of the importance of science and the scientific method and the awe that we experience that rekindled the enjoyment of the world and the universe, back into my mind.