Terminator Salvation star Sam Worthington is to play a lead role in the upcoming film of bestselling book The Shack, joining The Help star Octavia Spencer.

The Christian-themed 2007 book by William P Young stormed the best-seller lists, though it has caused controversy in the church with its inventive portrayal of the Trinity and other theological issues.

In the story, the main character suffers after the disappearance of his daughter; but an invite to meet with God changes his life.

Worthington, who also starred in Avatar, is thought to be playing lead role Mackenzie Allen Phillips, while Spencer is to play Father God.

The film is to be directed by British screenwriter Stuart Hazeldine, who co-wrote and directed the film Exam. He has also directed a short film called Christian, which re-imagines Jesus as a schoolboy who faces bullies in a tough inner city school.

Hazeldine tweeted on Easter Sunday: "'If Christ has not been raised our preaching is in vain, and so is our faith'. Happy Easter." 

The film is being produced by Lionsgate.