Goodman Brown very quickly proclaims that he kept his meeting with the Devil and didn't really wishes to proceed on his errand with the Devil. He says that he originates from a "race of fair men and great Christians" and that his dad had never gone on this errand and nor will he. The Devil rushes to bring up however that he was with his dad and granddad when they were flagellating a lady or smoldering an Indian town, separately. These demonstrations are humorous in that they were awful deeds done for the sake of good, and it demonstrates that he doesn't come
from "great
from "great