Reliable Research

The Pew survey (2014) is the most comprehensive, authoritative survey on the American religious landscape. They provide robust search tools that allow you to cut the data many different ways—by state, demographics, beliefs and practices, and social and political views.

Barna’s categories differ substantially from Pew’s. Whereas Pew uses mostly self-reporting labels, Barna is skewed to a grid based on their understanding of orthodox Christianity. They use a narrow definition of “evangelical” and include liberal/progressive Christians with “notional Christians.”

The National Congregations Study (2012 data; report released in 2015) is a comprehensive study of what religious congregations in the U.S. actually do. Data collection began in 1998 and researchers are tracking congregational trends over time. In addition to the 2015 report, you can manipulate the data yourself with the tools they provide.

The Hartford Institute for Religion Research has created an excellent portal page for religion research with links to numerous good studies, e.g., a database of U.S. megachurches (worshipping at least 2,000 persons per week) and studies on U.S. mosques.

Public Religion Research Institute conducts studies and provides e-news daily regarding the intersection of religion, culture, and politics. The CEO is Robert Jones, who authored The End of White Christian America.