The author's desire to promote holy living is notable. His arguments lack cogency. His premise is faulty. And he falls prey to some of the logic of which he accuses his opponents.
I was a little put off because this book spent a lot of time on anti-calvinistic discussion. If your theology is arminian in nature, then you will probably love this book. There is plenty of scriptural discussion on how to think about sin and our relationship with God, but it seems that every few pages calvinism was bought up to be refuted. I am happy to read arminian and calvinistic perspectives, but when the book content is a polemic against the other perspective, I consider it unhelpful.
Although the title of the book suggests that a definition is the authors primary function, the chapters are more frequently grounded on the doctrinal arguments between Armenians and Calvinists. Taylor does have much to say about sin and how we should think of it. In fact, chapter seven is one of the best chapters on hamartiology that I've every read. Unfortunately, the rest of the book too heavily focuses on Calvinism which serves more as a distraction than anything else. In fact, there were a few places where I found the author to be inappropriately rude toward our Calvinistic brothers and sisters. Doctrinally I agree with most everything in the book. As a writer, he is talented and I enjoyed his work. As a Christian brother, he could have found a better way to make his point than etching a deeper divide within Christian fault-lines that need more healing than highlighting.