Brhadaranyaka Upanishad - This book presents a lucid exposition of select portions of this Upanishad in the light of modern thought and modern needs. The Revered Swami has done this by freely drawing from contemporary scientific thought, biology, and physics, and by laying stress on the relevance of Vedantic ideas to these areas of modern thought.
The essential thing in religion is making the heart pure; the Kingdom of Heaven is within us, but only the pure in heart can see the King. While we think of the world, it is only the world for us; but let us come to it with the feeling that the world is God, and we shall have God.
-Swami Vivekananda