The Pilgrim's Progress
Expert critics think the second part is important, and brings in more ideas: "Part II, which appeared in 1684, is much more than a mere sequel to or repetition of the earlier volume. It clarifies and reinforces and justifies the story of Part I. The beam of Bunyan's spotlight is broadened to include Christian's family and other men, women, and children; the incidents and accidents of everyday life are more numerous, the joys of the pilgrimage tend to outweigh the hardships; and to the faith and hope of Part I is added in abundant measure that greatest of virtues, charity. The two parts of The Pilgrim's Progress in reality constitute a whole, and the whole is, without doubt, the most influential religious book ever written in the English language.