The tone of Pilgrim's Progress is earnest, exhortative, and comforting. Bunyan clearly wants readers to enjoy his book, using dramatic events like combat with giants and demons and enticing images of Heaven to pull them in and keep them reading. Yet he also expects them to take his subject matter utterly seriously; that's why he goes to such lengths, for instance, to defend his use of allegory as spiritually edifying and not merely as frivolous entertainment. His consistently earnest, even fervent tone offers little hint of irony or sarcasm; readers are meant to take the book's contents to heart.
The tone is exhortative, or morally encouraging, in the sense that it repeatedly urges readers to identify with the characters in both their struggles and successes, persevering in their own earthly "pilgrimages" even when they experience personal suffering, spiritual doubts, and other obstacles. Yet, despite this frequent sternness, it's also comforting—although it's the nature of any pilgrimage that challenges and even failures are expected, failure and even death never have the final say in the book. Even the worst of physical suffering, like Faithful's martyrdom, is just a gateway to endless happiness in Heaven; and any success a pilgrim experiences, or any rescue from trouble, is ultimately attributed to God, who is the protagonists' dearest companion throughout their journeys and eventually in the Celestial City. Such comfort is movingly evident at the River of Death, when Christian, even after all he's overcome, believes he will sink and drown; yet, when he thinks about Jesus instead of his own sinfulness, he suddenly finds the crossing from life to death easy, suggesting that no matter what obstacles a pilgrim faces, God will ultimately conquer them all.
