Summary: Concise but comprehensive might sound like a contradiction but I couldn't think of any other way to describe it. John Piper really introduced me to Jonathan Edwards, and between the two of them I would say that no other author has had as much of an impact upon me in the last few years as these two. Now Piper introduces us to Augustine, Luther, and Calvin also. This is the first book in a series of three and well worth the investment. I read it in my spare time in just 1 week, have the second book ready to go, but regret not purchasing the third at the same time. Piper's strength is not only in presenting one very compelling argument about the triumph of God's grace (or "Sovereign Joy"), but to do it by presenting numerous facets of the work of Augustine, Luther, and Calvin, which are easy to follow and understand, gives an excellent overview of their lives and ministries, and which leaves you wanting to (and feeling confident of being able to) read from the original sources. Every page was a gem. Be warned though, I got about 10 pages into the book then realised my mistake ... I should have read this book with a pencil and note pad in hand! There are so many great quotes from Augustine, Luther, and Calvin, not to mention Piper himself that you'll want to write some of them down to chew over later (or file away for sermon illustrations). This is an easy read and a great introduction the some major figures in church history, not to mention excellent food for the soul. In a day when people are so biblically illiterate as well as ignorant (or contemptible) of church history, this book demonstrates that our impoverishment is foolish and unnecessary. We need more books like this! I would have given it 6 stars if I could, simply on price, readability, and content alone.