10-year-old Bart Millard lives with his mother and abusive father Arthur in Texas. One day his mother drops him off at a Christian camp where he meets Shannon. Upon his return from camp, Bart finds his mother has left and movers are removing her belongings. He angrily confronts his father, who denies that his abusiveness was the reason she left. Years later, in high school, Bart and Shannon are dating. Bart plays football to please his father but is injured, breaking both ankles and ending his career. The only elective with openings is music class, so he reluctantly signs up.
J. Michael Finley
as Bart Millard
Dennis Quaid
as Arthur
Cloris Leachman
as Memaw
Brody Rose
as Young Bart
Madeline Carroll
as Shannon
Gianna Simone
as Dr. Avondale
Kevin Downes
as Singleton
Jason Burkey
as Mike
Rhoda Griffis
as Jen
Tanya Clarke
as Adele
Nicole DuPort
as Amy Grant
Priscilla C. Shirer
as Mrs. Fincher