The Christian movie star Jim Caviezel, who played Jesus in The Passion of the Christ, has said that daily prayer, Bible reading and mass helped him to portray Luke in the forthcoming film Paul, the Apostle of Christ.

In an interview with the Catholic News Agency (CNA) about the forthcoming movie, which is based on the Acts of the Apostles, Caviezel, who is a practising Catholic, added: 'Everything that I do is always with heaven's help.'

The actor told CNA that he relied on spiritual disciplines to portray holiness in the film, which premieres on March 23 and depicts the persecution of the early Christians in Rome under Emperor Nero, along with an imprisoned Saint Paul conveying a message of hope at the end of his life.

'I thought that that was one of the greatest parts of the script,' Caviezel told the CNA. 'Here is a beat-up old man in prison, facing execution. How can this man be a light to the world? But it's often through our struggles, our trials, our tragedies that triumph comes.'

In the film Luke is seen regularly visiting Paul in prison to document his story while composing Acts. Caviezel plays Luke serving the early Christian community in Rome as a physician, spiritual leader and writer.

'He [Luke] mentioned the Virgin Mary more than any other writer,' noted Caviezel. 'I use the rosary to focus, to pray.'

He went on: 'I go to mass every day and the eucharist is Christ in me. Everything that I do is always with heaven's help. It directs my path. It guides me. It is where I got my talent from. What I give back to God from what he has given me...he just multiplies it and blesses it in ways that I never thought possible.'

Caviezel added that he also has 'a great devotion to the patron saint of actors, Saint Genesius'.

The role of Paul is played by the British actor James Faulkner, who previously had supporting parts in the TV series Game of Thrones and Downton Abbey.

Faulkner, who was raised in the Church of England, also spoke to the CNA, saying: 'Well I'm happy to admit that Jim is a much more devout Christian than am I, and I drew from his faith whenever possible.'

Faulkner reflected that he was affected by preparing for playing Paul as he 'read and reread Paul's letters' in preparation for the role.

'Do I have more humility? Yes. Do I have more love for my fellow man? Yes. Is there a possibility of redemption even for myself? Yes, there is,' Faulkner said.

Faulkner said that the set of Paul, the Apostle of Christ felt different than his previous experience on the set of Game of Thrones. 'Being placed in a much simpler environment, and feeling entirely supported by those around you, and loved by those around you, I found to be an extraordinary experience,' he said.

Caviezel added that conversion and forgiveness are major themes of Paul, the Apostle of Christ. 'The greatest controversy of this film is forgiving at all costs, and that doesn't mean weakness or the acceptance of evil. It means meeting evil face-to-face...that's the hardest thing,' he said.

'Some of the most powerful dialogue centres around what true courage is,' Caviezel continued. 'Courage is ardent love. Love creates change by igniting a passion in each one of us. One person at a time.'

The movie is dedicated to the world's persecuted Christians. Its executive producer, Eric Groth, told the CNA: 'We were writing this script through those heavy intense times with ISIS and the problems that are going on in Syria and the Middle East.'

In a separate interview with Christian Today this week, Joaquin Phoenix revealed that he studied the four New Testament Gospels in preparation for playing Jesus in another movie out in time for Easter, Mary Magdalene, and spoke about how Christ's 'heart-wrenching' example in the Garden of Gethsemane and on the cross inspires him 'to be more empathetic and considerate and forgiving'.