Santiago and the fish are alter egos for one another, connected by the fishing line, and are both Christ figures. The book borrows biblical imagery to illustrate this symbolism. For example the story opens and closes with Santiago carrying his mast to and from the boat just as Christ carries a cross in the Bible. The side of the fish is pierced in the novel just as Christ's side is pierced in the Bible. Throughout the novel Hemingway will spend a paragraph describing something happening to Santiago and then the next paragraph will describe a similar situation with the fish.