Bunyan's allegory The Pilgrim's Progress is a narrated dream, where the main character Christian ventures from the City of Destruction to the Celestial City.

Christian is depicted as a man with a dogged devotion to his faith, determined to make his journey in order to be delivered back into the hands of God. On the way to the Celestial City, Christian and his companion Pliable encounter the Slough of Despond, which is made up of various negative emotions they must overcome to avoid sinking into the depths.

Various other lessons are imparted during the course of the journey, with Christian enlisting various allies as he navigates the perilous terrain and surmounts the obstacles thrown in his path. All along the way he carries a heavy pack upon his back, his burden, which refers to the difficulty many have in keeping authentically to their faith.

Published in 1678, this book has been hailed as one of the cornerstones of Christian allegory during the 17th century. Written by Bunyan while he was incarcerated for preaching without the permission of the Church of England, the book was later expanded when Bunyan attained his freedom.

In the centuries since its original publication, The Pilgrim's Progress has become a classic of Christian literature, having been released in many editions and widely translated.