It should be less than surprising to know that J.R.R. Tolkien was a Christian, and that he included Christian themes in his stories (especially the Lord of the Rings series). But exactly what does he say? Is Gandalf a Christ-figure? Is Samwise's humility and perseverence mirrored in the Bible? What illustrations does the friendship between Legolas and Gimli show? Tolkien's works aren't a direct allegory as are the novels of C.S. Lewis, so it may be a bit harder to tease out the truths.
This is where Ralph Wood comes in. His book, The Gospel According To Tolkien, seeks to detail the elements of Christianity in Tolkien's works. Readers should keep in mind that this book relies on the complete written works of Tolkien and so goes far beyond the movies directed by Peter Jackson. For those of you who haven't read the books, or have limited yourselves to the ones upon which the movies are based, you might find yourself lost at some of the references.
This book is definitely written for hard-core Tolkien fans. It's also written for those wanting a very detailed exploration into the Biblical themes of the books. While I found the discussions elightening, and will make me look at the source material in a different light, I also found it a bit dry, and couldn't read much at a time. That's not a bad thing, but I would not call this a casual read.
My recommendation? If you want a detalied study and are looking for deep discussions, and you are a big Tolkien fan, then pick up this book. If you've only seen the movies or want a lighter read, you may want to pass.