This book provides an in-depth introduction to the principles of 'A Course in Miracles.' It first explains the central ideas in the ego's thought system of sin, guilt, and fear, and its defenses of denial and projection. Next, the Holy Spirit's thought system of forgiveness is explained, showing specifically how it and the miracle undo the ego's chief defense against the Love of God: special relationships. Included also are chapters on the purpose of Jesus' life, and the story of how the Course came to be written.