In 2 Peter 2:1-11, Peter warns believers about the presence of false teachers who secretly introduce destructive heresies, leading many astray. He emphasizes that God did not spare the rebellious angels or the ancient world in Noah's time, bringing judgment upon them while preserving the righteous. Similarly, God condemned Sodom and Gomorrah, rescuing Lot, a righteous man, from their destruction. He assures that the Lord knows how to rescue the godly from trials while keeping the unrighteous under punishment until the day of judgment.