This comprehensive reference work investigates the global status, demographic reach, and institutional diversity of Christianity within the context of all major world religions and secular ideologies during the twentieth century. David B. Barrett, a noted missiologist and researcher, utilizes an extensive quantitative framework to map the expansion and fragmentation of Christian traditions. By synthesizing data from thousands of ecclesiastical jurisdictions, the text provides a rigorous statistical and descriptive analysis of religious adherence across the globe from 1900 to 2000.

Experts and scholars in the field of religious studies recognize this work as a foundational, encyclopedic resource for quantitative data on global Christianity. Readers frequently note the immense density of the statistical information and the objective, ecumenical approach maintained throughout the survey.