John Gill expounds on 2 Peter 2:4, emphasizing that God did not spare the angels who sinned, illustrating the severity of divine judgment against rebellion. He explains that these angels, once pure and holy, fell due to pride and a refusal to abide in the truth, leading to their eternal punishment. Gill warns that false teachers, like the fallen angels, will face similar consequences for denying the truth of the Gospel. He describes their current state as one of darkness and despair, reserved for judgment, highlighting the importance of remaining steadfast in faith. The sermon serves as a sobering reminder of the consequences of straying from God's truth.