Forget Dawkins, Harris, Hitchins, McGrath or Swinburne. Most of the questions and answers to issues of religious faith are in here. Read this, City of God and Summa Theologicae (Aquinas) and you'll see how trivial most modern popular discussion is. There is nothing new under the Sun! Well read and a worthwhile listen.
Once you get over the initially patronising tone of Walter Dixon's reading this is a genuinely interesting work. MacCullogh's agenda as a 'friend of Christianity' is apparent throughout and this is very much a study of Christianity from the outside with no proselytising mission. The audiobook can be confusing as several of the themes overlap, for obvious reasons, and it's more difficult to 'flick back a couple of pages' in an audiobook, so it can be easy to lose the thread from time to time. However, despite this the level of detail given to major thinkers and themes within the development of Christianity is useful and informative for everyone but the expert in this area. It is enjoyable to read / listen to a work from an author as comfortable citing Father Ted as St. Augustine. This is neither inaccessible to the beginner nor dumbed down to the point of meaninglessness. Well worth the 40 odd hours listening!
I really enjoyed this work, though I found getting your head around and remembering all the names difficult in an audio book! I had to Google a lot of them when I got to work just to help the names stick in my head! As an introduction I really enjoyed this and it was helpful in contextualising the interplay between Western and Islamic philosophy too. I'd recommend.