I heard a great deal of good things about this book and eventually bought it so I could read it for myself. Basically, Greg Boyd realized he had been achieved a very strong theological education, was teaching at a seminary and using his knowledge to write books and such in the hopes of leading people to Christ; all the while, his father was an atheist and they hadn't ever truly discussed all the reasons he doubted the existence of God. So Greg decided to start a letter correspondence (pre-email) with his father, allowing his father to ask or raise ANY and EVERY objection he had to the faith, with Greg being able to respond. His dad took him up on the offer and definitely did not hold back any punches. The book is simply a compilation of their correspondence back and forth, but provides a great dialogue over most of the key theological issues facing Christianity/atheists today. They decided to keep the original wording of the letters in tact, so as not to dilute the passion or bitterness his father had toward many of the Bible's teachings. On a few occasions, his father cusses or uses strong language to help illustrate his point, but overall, his father is an extremely deep thinker and raised a gauntlet of questions for Greg to answer. Greg did his best to do so and, well, you can read the book to see what happened as a result of their correspondence. Most reviews and such give it away, but even still, the correspondence is certainly worth the read.
I will add a disclaimer since my audience, yet extremely small, is certainly diverse theologically. Greg Boyd has been known for holding a few "controversial" stances theologically with respect to certain issues (most notably, open theism). Whether you agree with Boyd on this point or not I don't think is crucial to your enjoying this book, or any of his other writings, or not. It only comes up once in this book, so it certainly is not a huge component. In addition, whenever Boyd does go into a discussion of one of his more "controversial" views, he always provides the more contemporary views, held more widely by most Christians throughout history. At the end, he always states, "if you don't agree with me that's fine, I don't think it's something to get too hot and bothered by," or something to that effect. Essentially, as long as we agree on the fundamentals of the faith, whether you affirm open theism (for example) or not, that's fine. Boyd isn't trying to convince you, the reader, or his father of holding every small theological point he holds, but to convince you of the reality of Jesus Christ and why he matters in this world and in your life.
Let's keep the main thing the main thing.
I've loaned the book out to 4 people now haha and the list is growing. They've all really enjoyed it, so I can say, with 5 opinions in mind, it's definitely worth reading. Of all the books I've reviewed on here so far, it is by far the first I would recommend to anyone.