Soon after Christian and Hopeful meet up outside of Vanity, they encounter a rich pilgrim named By-ends. By-ends shares that he and his wife differ from many other pilgrims, and he uses personification to elaborate:
Secondly, we are always most zealous when Religion goes in his Silver Slippers; we love much to walk with him in the Street, if the Sun shines, and the people applaud him.
By-ends explains that he and his wife prefer religion that dresses in fancy clothes and parades in public on sunny days, garnering popular approval. He means that they are happiest to associate with religion that thrives amid affluence, that displays itself when things are going well, and that goes with the grain of popular acceptance. In other words, they avoid religion that's associated with the poor, that requires them to suffer in any way, and that earns the disapproval of society. Though By-ends thinks this is all just fine, Christian and Hopeful confront him about it, and Bunyan is clearly on their side: the entirety of the book thus far demonstrates that Christianity is not supposed to be about wealth, comfort, and simply going with the tide. Still, By-ends's frank preference for "Silver Slippers" religion suggests that such attitudes were common in Bunyan's day as they are now. Later, ironically, By-ends wanders into Demas's silver mine to dig for treasure and is never seen again.
In Part 2's Introduction, Bunyan addresses Pilgrim's Progress as if the book itself is a person, reassuring the book that it will be warmly received by its intended audience:
Wherefore my Second Part, thou need'st not be Afraid to shew thy Head; none can hurt thee, That wish but well to him that went before, ’Cause thou com'st after with a second store Of things as good, as rich, as profitable, For Young, for Old, for Stagg'ring, and for Stable.
Bunyan assures his book's Second Part that because readers loved the First Part so much, there's no need for it to be timid; it will be welcomed by those same readers. After all, the Second Part (which was published six years after the first) offers the same kind of edifying content that readers of all ages and spiritual conditions (whether "Stagg'ring" or "Stable") benefited from in the original. Of course, a book needs no such reassurance, and it's unlikely that Bunyan was primarily seeking to reassure himself, either. Rather, this personification is meant to assure readers that this second installment is indeed "as good, as rich, as profitable" as the first.
Bunyan also addresses objections to Pilgrim's Progress that have presumably come up since the First Part's publication:
But some there be that say he laughs too loud; And some do say his Head is in a Cloud. Some say his Words and Stories are so dark, They know not how by them to find his mark.
Criticisms of Pilgrim's Progress have included objections that the book is too frivolous or too imaginative for its religious subject matter ("laughs too loud," "Head is in a Cloud"). The image of a laughing, cloudy-headed book is connected to the controversy, mentioned in the Introduction to Book 1, surrounding Bunyan's use of allegory—that allegory is too obscure ("dark") for readers to understand Bunyan's point ("find his mark"). In rebuttal, Bunyan goes on to contend that joy is part of a Christian's experience just as tears are, and that imagination, including "dark" or obscuring language, entices a reader's mind, causing ideas to stick more firmly than they would if given as plain propositions. Simply put, just because Bunyan is dealing with religious subjects doesn't mean it's wrong for readers to enjoy themselves. To make that case, Bunyan pointedly uses personification, likely hoping that whimsy will persuade where straight argumentation might fall short.
