The author is a well respected statistician, and the book is extended case study in how to think about "unlikely" events. When is a coincidence just a coincidence, and when does it point to hidden causes at work?
Hand shows that extraordinarily rare events are commonplace. People can and will win the lottery twice. People can and will be hit by lightning three separate times and survive. None of these require a belief in miracles or supernatural interventions or cosmic synchronicity to explain them. All you need is a firm grounding in a small set of probabilistic and statistical laws.
The book is aimed at a non-technical audience. I learned a lot from it.