This paperback deserves to become a classic on the subject of the Holy Spirit. Starting with the scriptures, using good illustrations and quotations from other writers (especially Calvin) the author leads the reader along the path of discovery into the third person of the Trinity. The book is structured in a similar way to one of Paul’s letters. The first chapters cover doctrine and the later chapters apply the doctrine. The chapters on the Trinity and the baptism of the Spirit are particularly helpful, providing clarity into an area where there is much muddled thinking today. When he turns to application, the author wisely points out that although the gifts of the Holy Spirit are “fascinating and exciting” the fruit of the Spirit is much more important: it is “the mark of our progress in sanctification.” This book will help believers especially those struggling with the concept of the Trinity and those confused by the work of the Holy Spirit. The book would also help a preacher preparing a topical series on the Holy Spirit.