4 For if God did not spare angels when they sinned, but sent them to hell,[a] putting them in chains of darkness[b] to be held for judgment; 5 if he did not spare the ancient world when he brought the flood on its ungodly people, but protected Noah, a preacher of righteousness, and seven others; 6 if he condemned the cities of Sodom and Gomorrah by burning them to ashes, and made them an example of what is going to happen to the ungodly; 7 and if he rescued Lot, a righteous man, who was distressed by the depraved conduct of the lawless 8 (for that righteous man, living among them day after day, was tormented in his righteous soul by the lawless deeds he saw and heard)— 9 if this is so, then the Lord knows how to rescue the godly from trials and to hold the unrighteous for punishment on the day of judgment. 10 This is especially true of those who follow the corrupt desire of the flesh[c] and despise authority.
As Peter talks about the destruction of these so called prophets, he points to other examples of those who were punished for their wickedness. Interestingly, we even see angels who were corrupt and fallen. We always think of angels as good and going around doing good deeds for God, but we see that angel's have a will too. But their were also times in the bible God punished extreme wickedness. If you read about these situations, the sinfulness was so bad God wished that he had ever made some of these people. No, Peter does not candy coat it that some are bound for eternity apart from God, which is also called hell.
Many look at these passages and say, "Wow God is so judgmental to these people!" And the answer is, "Yes he was!" God is great and merciful, but He is also just. Romans 6:23 says, "the wages of sin is death, but the free gift of God is eternal life." There is one thing we forget. Without judgment there is no mercy. Without acknowledging our sin, we can't receive God's grace in Jesus Christ. One of the things to remember in these Old Testament passages is that God warned these people to repent of their sinful ways, and gave them time to turn back to him. But their hearts were so hardened, they could not receive God's grace and mercy like Lot and Noah did.
But the context is that Peter is encouraging the believers that when it seems like evil is winning the day, as they were being persecuted, there would come a day of judgment. Although there will be a day of judgment for all people, God waits patiently for those who don't yet know Him to repent. God is the God of the second, third and fourth chance. God doesn't want any to perish but all people to come to eternal life. There will come a judgment day for us too. And in our judgment we get what we don't deserve, which is forgiveness of our sin through Jesus' death and resurrection. The judgment we deserved Jesus took on the cross. Therefore we don't need to fear judgment day. We can live our lives in thanksgiving to God, and ask God to use us to bring others back to him. We pray for others that God would soften their hearts so that they will receive God's grace and come into a right relationship with Him.
Take a moment to thank God the Father and God the Son for getting what you didn't deserve. Pray for those who you think might not be right with God.