The author introduces some basic concepts and symbols of the “Secret Doctrine” - the unique work of our great compatriot Helena Petrovna Blavatsky, Messenger of the Great Himalayan Teachers. This book, which is a synthesis of science, philosophy and religion, contains Revelations of the Scientists of Shambhala about the origin and development of the Cosmos, Earth and humanity. In the third part of this publication, the author offers essays about some of the Great Teachers of humanity, written in the light of the “Secret Doctrine”, and also gives their philosophical and poetic interpretations of paintings by Nicholas Roerich dedicated to these Teachers. Also given is the concept of the Teaching of Living Ethics (Agni Yoga), which is the crown of the “Secret Doctrine” and, by Decree of the Lord of Shambhala, transmitted to humanity by his collaborator Elena Ivanovna Roerich. The publication is intended for a wide range of readers, primarily for young people interested in the laws of life not only in the visible (physical) world, but also the invisible (superphysical), which, as the “Secret Doctrine” claims, makes up most of the Cosmos.