Why? Philip Pullman wrote Compass as a trilogy to expose the Catholic Church. However, the script was diluted as to lose the soul of his first book, as Pullman has been quoted to say: "I want to kill God in the minds of children." Even then, as an atheist cannot be elected President in the U.S. anti-religion films also do not do well, especially if condemned by the Vatican.
The Chronicles of Narnia represent seven novels by C.S. Lewis, written for children with Christian themes. They have sold 100 million copies in 47 languages.
The third of this series, The Voyage of the Dawn Treader, opened this week in 3D, and could well head to the top. (By the way, the first Narnia is on ABC tonight at 7PM).