Since its first publication in 1678, The Pilgrim's Progress has never been out of print -- and that fact reflects the timeless relevance and wisdom of this long-form Christian allegory. The text follows the journey of the title character, Christian, as he makes his way from the earthly sphere represented by the "City of Destruction" to the "Celestial Sphere," which represents Heaven, battling sin, temptation, and every other conceivable vice along the way.