Here is the first modern publication of a great spiritual treatise by John Pordage, leader of a non-sectarian Christian mystical group in 17th-century England. In a lucid, modern style, Pordage explains the hidden nature of God and how we may come to direct spiritual experience for ourselves. Among Pordage's subjects are the nature of the Trinity, how nature came into being, what angels and spirits are, and how to awaken the eye in the heart to authentic spiritual understanding.