It is my belief that in the very near future this book is going to be the go to text for the topic of Protestantism at the collegiate and even seminary level.  All I can say is thank goodness.  This book is great because even though it has the breadth of a textbook it reads very well.  I might even describe it as compelling.  Ryrie does a good job of delving into the many different streams of Protestantism while acknowledging and expounding upon their common roots.  This book will not only be a vital tool for the student of religion, but is also a great text for the student of general history because it highlights the ever present influence of Protestantism on the world as we have come to know it.