After my third time through this book, I have a renewed appreciation for Thomas's insightful and sensitive reading of spiritual classics from the monastic, mystical, contemplative, and Puritan traditions. While Thomas doesn't address theological differences between Protestant, Roman Catholic, and Orthodox Christians, he does issue warnings here and there, especially about the dangers of legalism. Thomas also leans a little too much toward asceticism for my taste. But in spite of those criticisms, Thomas does a masterful job of culling insights from a broad swath of classic spiritual text, applying these insights to contemporary believers, and organizing them in a fresh, relevant way. There are insights in this book that I'm not sure I've found anywhere else - at least not expressed elsewhere with such clarity. I'm thinking especially of chapter 11, "The Seasons of the Soul," with its helpful discussion of spiritual climates, terrains, and stations in life. Final comment: I think Thomas's body of work has been very helpful in pushing Evangelicals to greater spiritual depth. But, much like A. W. Tozer, I think Thomas's work needs to be balanced with other emphases in spiritual life, found in books by authors like J. I. Packer, Don Whitney, and Jerry Bridges.