C. S. Lewis was famous both as a fiction writer and as a Christian thinker, and scholars sometimes divide his personality in two. Yet a large part of Lewis's appeal, for both his audiences, lay in his ability to fuse imagination with instruction. "Let the pictures tell you their own moral," he once advised writers of children's stories. "But if they don't show you any moral, don't put one in."
I am not a fan of this trend where people keep publishing the Narnia series in the wrong order. There is no good reason to read the books in chronological order until after you've already read the books in their original published order:
The Lion, the Witch, and the Wardrobe 
Prince Caspian 
The Voyage of the Dawn Treader 
The Silver Chair 
The Horse and His Boy 
The Magician's Nephew 
The Last Battle 
Otherwise, it's a great series.