I've been interested in church history recently, and I keep coming back to the torturous struggle that Christianity had in clearly defining the Trinity. I was having a hard time understanding what the big deal was, so I looked up what some respected people said was the best book available about the Trinity, and it was this. I was not at all disappointed.

It was not quite what I expected: it reads more as a defense of the doctrine of the Trinity contrasted with the many misunderstandings/heresies around it. It seems like a systematic discussion of the doctrine (what I was expecting) only second to this primary role. However, having read the book, I think this is probably better. With a concept like this that's so hard to pin down precisely, it's often more helpful to define what it's not (a point he makes directly in the book), since what it IS is something beyond our ability to understand fully.

I think every Christian should read this book or something like it to make sure they have a good understanding of this vital topic. Despite being a very difficult subject and despite the book going into details of Greek verbs and such, it never felt dry or boring.