The film tells the story of Paul, who was known as a ruthless persecutor of Christians prior to his conversion to Christianity. The plot focuses on his becoming a pivotal figure in the formation of the early church before being executed by Emperor Nero in Rome.
The setting is Mamertine Prison in Rome where Paul has been imprisoned because he has been deemed a threat to the Roman Empire. Emperor Nero has sentenced him to death. Paul's long journey to this place has been eventful. At one time—as Saul—he persecuted Christians relentlessly. And then he converted to Christianity. That is when Paul became the persecuted. His path has involved degradation, torture and shipwreck.
At Mamertine, he interacts with his jailer Mauritius and Luke the evangelist. Mauritius is curious about Paul and seeks to learn how this one man can have such a profound effect on the empire. Luke, his dutiful caretaker, takes this opportunity to write the Acts of the Apostles, a history of the early church. Meanwhile, the infamous persecution of the Christians under Nero is in full effect. As the time draws near to the date of his execution, Paul struggles with God's forgiveness for his sins. He must remember God's grace and near the end says, "where sin is prevalent, grace abounds more."
In an interview with Variety, Berden said that one of the main themes of the film is forgiveness: "Paul changed from murdering Christians to becoming their unlikely leader. His life personifies ‘forgiveness,’ a concept that seems almost impossible today — but desperately needed."