Theosophy: An Introduction to the Spiritual Processes in Human Life and in the Cosmos

Theosophy is a key work for gaining a solid footing in spiritual reality as described by Rudolf Steiner. It is organized into four parts. First, Steiner builds a comprehensive understanding of human nature: physical bodily nature
soul qualities
spirit being, or "I"-being
and the higher spiritual aspects.

In the next section, Steiner offers an extraordinary overview of the laws of reincarnation and the principles of karma, as we pass from one life to the next. This prepares us for the third section, in which he shows the various ways in which we live―
during life on earth and after death and in the three worlds of body, soul, and spirit.

Finally, we are given a succinct description of the path of knowledge, along which each person can begin to understand the marvelous and harmonious complexity of the psycho-spiritual worlds in their fullness.