The very fact that this book is written by the Bishop of Edinburgh only reinvorces the lack of necessity for God in a moral system. To quote Holloway "We either admit that God is, to some extent at least, a human construct that is subject to criticism and evolution, or we weld religion to unsustainable prejudices that guarantee its rejection for the best, not the worst of reasons, so that to abandon it becomes a virtuous act of revolt against an oppressive force that imprisons rather than liberates humanity."
This is a refreshing and well written book and in no sense is it a sermon, quite the opposite.