The previous commenter obviously didn't read the blurb on the back of the book before purchasing. How can you expect a book on gangwars in Brazil to not be violent? The words across the top of the front cover summarise the book, and indeed it is a stunning masterpiece.
This book is probably the most violent book I have ever read, yet at the same time, the typically short and sharp violent paragraphs, many of them self-contained stories in themselves, are used as a way to set the scene and for the reader to understand the morals and outlook of those in the City of God from several perspectives.
The book feels well-organised, and although has a slightly less direct storyline than the film of the same name, the book is by far much more memorable. Lins does an excellent job of making the city real by making characters arrive, leave, grow up and die throughout the course of the novel. The book never feels static, it feels alive - maybe because it is reportedly based on a true story. His descriptions of everything, from violence to sex to scenery of Brazil are carefully-crafted and page turning, frank yet engrossing.
This is an amazing book and I would highly recommend that anyone who likes good books makes a purchase of it. I cannot recommend it enough. Yes, it's is violent but it really has a unique character and something about human nature, horrific or otherwise, that really shines through.