Shawshank Redemption – useful revision?

This might be a useful film to watch for RS GCSE students thinking about forgiveness, redemption, custodial sentences and rehabilitation, however it may also be used as a media source in Unit 1 Believing in God. It shows the prison governor referring to his Christian beliefs by quoting from the Bible and the prisoner responding. Is this all a negative portrayal of Christian beliefs or positively showing how a prison governor is aided by his faith?