40 Questions is a 5-book series with 5 released primary works first released in 2007 with contributions by Benjamin L. Merkle, Robert L. Plummer, Thomas R. Schreiner, John S. Hammett, Phil A. Newton, Matthew Barrett, Jason S. DeRouchie, Oren R. Martin, Andrew David Naselli, and Matthew Aaron Bennett.
5 40 Questions
2010 • 2 Readers • 354 pages • 5
5 40 Questions
2010 • 1 Reader • 256 pages
Planned book of 8 40 Questions
1 Reader • 3
5 40 Questions
2015 • 1 Reader • 352 pages