Modern cosmology is a fascinating area, with a constant stream of new discoveries about the universe. However, to have more than a superficial knowledge of the subject requires some acquaintance with Einstein's equation from general relativity, which can be intimidating for the newcomer to the subject. This book provides an accessible introduction to the consequences of this equation. This is mostly via biographical details of Einstein's life, but also involving the other major players in the field, including experimental test of GR and earlier work done on non-euclidean geometry. The later chapters get on to the recent work on the accelerating expansion of the Universe, and how this is related to Einstein's 'greatest blunder', that is the cosmological constant term of his field equations.
I'm always suspicious of science books with 'God' in the title, fearing they might be some sort of phoney theology. This is not the case here, Aczel has taken Einstein's use of the word (as in God does not play dice).
I read this book looking for information about the early solutions to Einstein's equations of General Relativity - the work of de Sitter, Lemaitre and others - but it turned out not to have as much detail as I wanted. However, it does have a lot of information in a fairly compact book, and is well worth reading.