Start with high-confidence religion & society books, then narrow by subgenre or adjacent topics.
Church Planting in Post-christian Soil
Christopher James
God Gave Rock and Roll to You
Leah Payne
New Faiths, Old Fears
Bruce Lawrence, Bruce B. Lawrence
Contemporary Debates in American Reform Judaism
Dana Evan Kaplan
Inside Scientology
Janet Reitman
A Gospel of Shame
Elinor Burkett, Frank Bruni
Unintended Reformation
Brad S. Gregory
Violence and the Sacred
René Girard
The Orwellian World of Jehovah's Witnesses
Gary Botting, Heather Botting
Given to the Goddess
Lucinda Ramberg
Religious Affects
Donovan O. Schaefer
Islam in Practice
Reinhold Loeffler
Being Muslim
Haroon Siddiqui
Revolution
George Barna
The Spiritual Virtuoso
Marion Goldman, Steven Pfaff
Christmas Unwrapped
Richard A. Horsley, James Tracy
Aspects of Islam
Ron Geaves, Ronald Geaves
Cults Like US
Jane Borden, Simon & Schuster Audio
Reporting Islam
Elizabeth Poole
Religious Activism on Campuses in Togo and Benin
Frédérick Madore, Frederick Madore