This is actually a 3 volume list of books: a text, a workbook and also a teacher's guide, that I read from repeatedly, and have for the previous 31 decades. It is among the most important spiritual messages of our time. The Course combines 21st Century psychology with non-dualistic metaphysics. https://www.youtube.com/channel/UCXpL4OXSmktqlP6_S5p5jIQ