Final answer:
In John Bunyan's 'The Pilgrim's Progress,' the character Atheist laughs at Christian and Hopeful for their pursuit of the Celestial City, claiming that after 20 years of searching, he has found no such place.
Step-by-step explanation:
The character who laughs at Christian and Hopeful about their journey because he has been searching for the Celestial City for 20 years is Atheist.
This occurs in John Bunyan's allegorical novel, The Pilgrim's Progress, where Atheist claims he has found no such place as the Celestial City and mocks the pilgrims for their faith and perseverance. Despite this discouragement, Christian and Hopeful continue on their journey, keeping their faith intact.