These lectures were given in 1922, midway between World War I and Steiner's death in 1925. They will be of particular interest to anyone wanting to comprehend Rudolf Steiner's mature understanding of his mission: 'enchristing' the world. The first two lectures constitute a call to arms or return to basics. Steiner speaks existentially and phenomenologically, building upon recognizable descriptions of actual experiences. His theme is the three states of consciousness (waking, dreaming, and dreamless sleep), and he shows how these ordinary human functions have initiatory possibilities. The next four lectures deal with the evolution of consciousness in relation to the universal significance of the Christ event. Through the resurrection, Christ's being entered earthly evolution. As a result, we see the world differently. Where ancient humanity experienced, 'Not I but the divine spirit around me', we can experience, 'Not I, but the Christ in me'. With this insight, we reach the heart of this volume - esoteric Christianity. For Rudolf Steiner, the most important task for human beings is to learn to overcome death by uniting with the Christ, who overcame death.Humanity's survival depends upon the 'enchristing' of the world. It is the purpose of anthroposophy to bring this reality into world evolution, to enable all religions and all human beings to experience the new reality. The topics include: The Three States of Night Consciousness; The Changing Experience of Breathing in the Course of History; The Inquiry and Formulation of the Cosmic Word in Breathing In and Out; The Teaching of the Risen One; The Threefold Sun and the Risen Christ; and more. Each edition in "The Collected Works of Rudolf Steiner" series contains an introduction, a relevant chronology of Rudolf Steiner's life, and an index. This volume is a translation of "Das Sonnenmysterium und das Mysterium von Tod und Auferstehung: Exoterisches und esoterisches Christentum".