I am someone who has always wanted and desired a rational faith based 99.9% on rational belief and 0.1% on faith. When I was sent on a local alpha course, I didn't want it to be a brain-washing exercise, and so I wanted to ask heavy questions and read books which had conviction and truth.
Having been given this book, I thought this was part of the brain-washing and that it would just tell me what I wanted to hear and ignore the hard stuff. How wrong was I!
For a start, it is hard keeping to the day by day discipline, even though it is only about 3-5 pages a day. I found I got to day 10 and then thought 'oh nuts - I haven't read anything', so I promptly read all ten days in one go. Unexpectantly, it turned out quite hard hitting, and actually argued Christianity from a rational point of view. I found it dealt with belief in a very logical way and answered various questions I had in mind before coming.
Of course, this is making it sound as if I was actually brain-washed and that this book or the course totally converted me! I did object to some bits of the book (like where it says you must give up everything else and just follow God), although this does not diminish the fact that it is a well argued and helpful book, which gives an outline of Christian philosophy and a rational argument for it.
For someone just starting out in thinking of being Christian, I'd say this book would be well worth a read. For those people (like I was) who are agnostic or cynical, this book is essential. In fact, on the basis of this book, may I recommend those starting out in Christianity do not accept any answers and continue questioning, for that is how strong faith is built.