The character JT is short for John Townsend in the movie. Dr. John Townsend is a real Christian psychologist who also is credited with pioneering in the field of Christian counseling around the World. He lives and has a radio show in Southern California.
The substance abuse program that Cory (Scott Elrod) is ordered to attend, Celebrate Recovery, is an actual program founded at Saddleback Church by John Baker. John appears in a non-speaking role in several shots of the Celebrate Recovery meetings.
At the 2012 Celebrate Recovery Summit at Saddleback Church, John Baker (founder of CR) mentioned that the testimonies featured in the film depiction of the CR meetings were based on actual testimonies. (Of course, the testimonies of the main characters were created for the plot.)
The team Cory is coaching is named the "Bulldogs". They are named after the actual Okmulgee High School's team mascot.