The Pilgrim's Progress
Some phrases from the book have become part of the English language, just as many English expressions come from the Bible. We often talk of a 'Slough of Despond' (when we feel a problem is too big for us). The expressions 'Vanity Fair' and 'House Beautiful' are also quite familiar. There are a large number of references to the book in later literature, and Bunyan's idea of how to tell a story has been borrowed and adapted many times.