Sam Worthington plays the father of a missing girl who is suspected to have been murdered. 

He receives a letter which is an invitation from God, to come visit The Shack. 

Written as a contemplation about the writers feelings towards God, the book went on to sell millions. I’ve read it too and it’s a good adaptation. Sure it’s a little sappy but I also think it’s a profoundly thoughtful story. If the story speaks to you at all then I’d recommend it.