How does one graphically portray "Lutheran" Sweden or "Catholic" Spain, where 98% of the population is claimed but only 3.6% and 15%, respectively, are actually practicing? How many Orthodox Christians are left in Russia and other states of the former USSR? How to reckon the number and life of Christians persecuted in China or Indonesia? Atlases are generally limited to sketching political hegemony, along ethnic and national lines. Indeed, the...