This book can be called a handbook of spirituality. Thoughts are simple, but challenging. It fills the vacuum of a reliable source book that treats the concept of Christian/Catholic spirituality from a broader perspective. This book tells the reader that spirituality is proper relationship, and sin is broken relationship. The ideas are presented in this book in a very scientific, logical manner and in a readable style. The worth-mentioning number of endnotes shows the richness of the book.