I read most of the older reviews on here before purchasing this book. Overall, it was a good read. It gave a good overview of the history of Christianity, from Christ's life to the turn of the 21st century. Shelley covers Christianity's rise and spread systematically, covering challenges to the church and the church's response in all different ages, from Gnosticism to post-modernism. He also ties the history of the church to the history of the parts of the world the church is found in; as a result, I ended up with a better understanding of 'secular' history, as I read how the church interacted with governments and important people to influence world history. One of the nice features of this book is that, at the end of each chapter, there are recommendations of books to read for further study on that chapter's topics.
As noted in other reviews, of course, this book has its faults. First of all, the author's tone toward the Roman Catholic church in general, but especially after the rise of popes in the late fifth century, is disapproving at best and hostile at worst (I say this as a life-long Protestant). However, this tone changes considerably once he reaches the post-WWII era and the Vatican II council, which he frames as the Catholic Church coming out of its Counter-reformation fortress. Secondly, the eastern churches are barely mentioned after the church council age. Russian Orthodoxy, for example, is mentioned in a passing paragraph, then ignored until the author describes the rise of communism in the 20th century. I would hope that, in a 4th edition of this book, Shelley would neutralize his tone toward the historical Catholic church, and add more information regarding the church in the East.
All in all, I am glad to have read this book. Even with its faults, I would recommend this book to someone who has not previously studied Christian history.