Description by Wikipedia:
"Cited as the first novel written in English."
The allegory of this book has antecedents in a large number of Christian devotional works that speak of the soul's path to Heaven, from the Lyke-Wake Dirge forward. Bunyan's allegory stands out above his predecessors because of his simple and effective prose style, steeped in Biblical texts and cadences. He confesses his own naïveté in the verse prologue to the book:
"I did not think
To shew to all the World my Pen and Ink
In such a mode; I only thought to make
I knew not what: nor did I undertake
Thereby to please my Neighbour; no not I;
I did it mine own self to gratifie."
Bunyan's inspiration? Due to many similarities - some more definite than others - it could be argued that he had access to Dante's Commedia. The Pilgrim's Progress may therefore be a distillation of the entire 'pilgrimage' that the 14th Century Italian penned.
Because of the widespread longtime popularity of The Pilgrim's Progress, Christian's hazards - whether originally from Bunyan or borrowed by him from the Bible-the "Slough of Despond", the "Hill Difficulty", "Valley of the Shadow of Death", "Doubting Castle", and the "Enchanted Ground", his temptations (the wares of "Vanity Fair" and the pleasantness of "By-Path Meadow"), his foes ("Apollyon" and "Giant Despair"), and the helpful stopping places he visits (the "House of the Interpreter", the "House Beautiful", the "Delectable Mountains", and the "Land of Beulah") have become commonly used phrases proverbial in English. For example, "One has one's own Slough of Despond to trudge through."