Bunyan used realism when he wrote his sermons for the church, then later extended them to sell. The realism is there to tell a lesson and he used details to make the “graphics” more comprehensive for the human mind during the 1600s.
However, not all Bunyan’s works were realistic. He used several metaphors when he was writing. In Pilgrim’s Progress, when Christian takes his journey through the wilderness, he has a choice: follow the path to God, which happens to be climbing a mountain of loose lava rocks, or to go on an easier path. Christian and Faithful has two other men who had earlier joined him on his journey, but they split up to take three different paths. One man took a path and was lost and couldn’t find his way back. The other man went on a different path and was attacked by a monstrous creature. (Part 1: Stage 8)
The metaphor that Bunyan was using is that the easy paths aren’t necessarily the path God has for you, and that through trials and tribulations, God will be there for you. He will guide your way, and “Be not burdened with times of sorrow” (I’m Free