It's rather lovely, I think that the Pope uses in his own book a phrase (which he applies to the parables of Jesus) which aptly describes this fascinating book: "...it not only or even primarily adds to what we know, but it changes our lives."
In Jesus of Nazareth, Our Holy Father presents a vision of primary events of the Gospels (this volume covers significant stories chronologically from the Baptism of Our Lord through the Transfiguration - a second volume is expected in the future). He delves into these Gospel stories (many of which are commonly taken for granted - both because we've heard these stories since we were young and because we're missing some of the background details that add depth and additional significance to these stories) to help bring Our Lord to life for modern readers.
Here are the basic Gospel stories that are covered in the text:
The Baptism of Jesus
The Temptations of Jesus
The Kingdom of God
The Sermon on the Mount
The Lord's Prayer
The Parables (with an emphasis on The Good Samaritan, The Prodigal Sun and the Rich Man and Lazarus)
Images from St. John's Gospel (Water, Vine and Wine, Bread, and the Shepherd)
Jesus Declares His Identity (The Son of Man, The Son, "I Am")
Here's a sampling of the style and content of the book, taken from the chapter on the Our Father in which the Pope discusses what we mean by "Hallowed be Thy Name".
God establishes a relationship between himself and us. He puts himself within reach of our invocation. He enters into relationship with us and enables us to be in relationship with him. Yet this means that in some sense he hands himself over to our human world. He has made himself accessible and, therefore, vulnerable as well. He assumes the risk of relationship, of communion, with us.
The process that was brought to completion in the Incarnation had begun with the giving of the divine name.... God has now truly made himself accessible in his incarnate Son. He has become a part of our world: he has, as it were, put himself into our hands.
This enables us to understand what the petition for the sanctification of the divine name means. The name of God can now be misused and so God himself can be sullied. The name of God can be co-opted for our purposes and so the image of God can also be distorted. The more he gives himself into our hands, the more we can obscure his light; the closer he is, the more our misuse can disfigure him. Martin Buber once said that when we consider all the ways in which God's name has been so shamefully misused, we almost despair of uttering it ourselves. But to keep it silent would be an outright refusal of the love with which God comes to us. Buber says that our only recourse is to try as reverently as possible to pick up and purify the polluted fragments of the divine name. But there is no way we can do that alone. All we can do is plead with him not to allow the light of his name to be destroyed in the world.
He elucidates the various Gospel stories from many angles, though certain patterns emerge. In many places, he discusses and refutes modern theories about the Life of Christ (many of which have the common thread of doubting the historical validity of the Gospels). These are usually the most difficult portions of the book to follow. I found it helpful to underline principal portions in order to keep a particular thread fresh in my memory. Brief notes on the various threads might also be helpful.
He also references Eastern imagery from traditional icons and what we have learned from Tradition (from the teachings of the Church Fathers) about the various Gospel passages.
This is a life-changing book. There are many stories, like the Transfiguration, that I had little understanding of to begin with and will never hear or think about in the same way again. I studied this over the course of a school year with a group of high school students. We studied approximately 10 to 15 pages at a time and discussed everything in depth. I don't think it's a book that most high schoolers could read on their own. Reading it in chunks together allowed us to delve into it more deeply (I'm certain that I got more out of it than I would have if I had read it on my own.) The discussions provided an opportunity to clarify confusing parts of the text (many times I was able to provide some helpful background info such as an explanation of a philosophical idea). The students really enjoyed the book and got a lot out of it. Besides the obvious benefits of the content of the book itself, they're now less intimidated by an "intellectual" book and understand that it's okay to just make a beginning in reading such a book and that it's perfectly normal to get more out of such a book every time they read it.
For those who might be interested, I wrote a number of blog posts on this book while I was studying it. You can read them here.