Maps add to one's historical understanding of the great religions, for example the Map on the Church of Rome and the Protestant Reformations shows the distribution of Catholic and other Christian believers. The map on The Buddhist World from the 1st to the 9th Century is instructive. This book, however, is a textbook survey and not an atlas (because there are not enough maps). It reads like a lengthy encyclopedia article with a few maps of the major world and ethnic religions.
The major religions Christianity, Islam, Hinduism, Buddhism and Judaism are covered, but unlike other surveys the coverage is extended to the long lost ancient religions (including ancient Greece and Rome), shamanism, Amerindian religions, traditional African religions, Shinto, Jainism, Sikhism, Zoroastrianism and others. Most of the 14 authors are academics with a "world reputation". The appendix has a useful 23 page chronology of important events under each religion. On balance this is an accurate historical outline and a framework for academic study, but misses the feel for the religions. With subject index and proper names index.