The author had quoted from this Upanishad and explained its ideas in several of his lectures, class-talks, and conversations. All this material, spread throughout the nine volumes of his Complete Works, has been brought together in this book for the first time. What makes this compilation a treasure trove of original ideas and masterly insights is that the author goes straight to the heart of the subject to focus on the essentials, and to evolve practical methods from abstract principles.
True religion is not talk, or doctrines, or theories, nor is it sectarianism. It is the relation between soul and God. Religion does not consist in erecting temples, or building churches, or attending public worship. It is not to be found in books, or in words, or in lectures, or in organizations. Religion consists in realization. We must realize God, feel God, see God, talk to God. That is religion.