Currently undergoing a dramatic renaissance, the subject of religion has been attracting considerable media attention. However, far too littleis known about people’s individual religiosity and the social effects and dynamics of religion. That which is known has become particularly important in a context of growing religious plurality and globalization, where interactions between societies with different cultural and religious backgrounds are increasing. To expand upon this knowledge the Bertelsmann Stiftung—in cooperation with sociologists, psychologists, theologians and religious studies experts—has developed the most advanced instrument to date to examine the various dimensions of religiosity: the Religion Monitor. A core element of the Religion Monitor is a quantitative representative survey of 21,000 people of all major faiths that was conducted around the world. This publication, which is the scholarly complement to the popular publication published in 2008, includes original contributions by renowned experts in which they examine and assess the Religion Monitor survey findings. The enclosed CD-ROM contains all findings for each of the 21 surveyed countries and the methodology reports.