This book deals with the existence of humans, who consist of body, soul, and spirit. Like everything in the universe, they are an energy body. The universal life energy, the universe, is everything that exists. Energy is eternal and imperishable; it only changes its form. Therefore, humans, as energy bodies, are also imperishable. The earthly lives of humans are described, and it is shown how they are a part of nature and why human evolution occurs. The creation of the first humans, the subsequent earthly lives, death, as well as spiritual life and the following earthly lives in other bodies are also addressed. Information about the spirit world, the spiritual guides of humans, guardian angels, and the development of humanity is another topic, as well as the contacts of humans with the spirit world. The book concludes.