Twain will essay the role of Jeremy Camp's mother Terry in the film, while Robertson will play Melissa Henning, who married Jeremy in 2000.
Roxburgh is set to star as Melissa Hennning's older sister and Parsons will play a rock star friend who mentors Jeremy.
Jon and Andrew Erwin will direct the film, which gets into production this month.
The Erwin brothers are producing the project along with Kevin Downes.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)