According to the author, 'Union with Christ' has made a sufficiently strong "comeback" to beg the question why another book is needed. His answer is this book is intended for a reader who knows nothing about the doctrine, and this was true of me. I thought it was an "old fashioned doctrine" rarely mentioned these days. Ferguson, however, writes lucidly and elegantly. The book is neither too simple nor too technical. The book is nicely printed on good paper. I looked forward to reading a chapter each day. I realise now that Christian friends are frequently talking about 'union with Christ' without knowing it as a doctrine. It is relevant and helpful.