John Gill expounds on 2 Peter 3:6, emphasizing the historical account of the flood as a demonstration of God's judgment on a corrupt world. He explains that the flood was a universal event that destroyed all life except for Noah and his family, illustrating the seriousness of sin and the reality of divine retribution. Gill argues against the scoffers who claim that all things remain unchanged since creation, highlighting that God's intervention in history proves otherwise. The sermon serves as a reminder of God's sovereignty and the eventual fulfillment of His promises, including future judgment.