The Greek word for world, kosmos, denotes order, a system, the world with its inhabitants. The earth in the preceding verse became the world in this verse, not merely the earth, but the earth with its inhabitants in a system. This refers to the world in Noah’s age, which was judged by God with the flood due to the sinfulness and ungodliness of that age (Gen. 6:5-7, 11-13, 17). This book is concerned mainly with the divine government and all its judgments. The first judgment on the world was the one executed by the flood in Noah’s day, which cleared up that ungodly world. This thought must have been in Peter while he was writing this verse. It implies that this age of apostasy will also be judged on the day of the Lord’s appearing, as it was judged in the day of Noah (Matt. 24:37-39). The word “then” in verse 6 refers to the age of Noah.
The word “flooded” in verse 6 refers to the flood of Noah’s time, the flood that caused the earth to be destroyed. The word “perish” means destroyed, demolished, laid waste (Gen. 6:13, 17). The earth, therefore, did not remain the same, but had a change, a cataclysm, by being flooded with water, and was destroyed. Here we see Peter’s strong argument against the heretical mockers. They said that “all things continue as they were from the beginning of creation.” But actually a cataclysm came upon the earth because of the ungodliness of its inhabitants. This implies that the present world will not remain as it is, but will also have a cataclysm by the Lord’s coming with His judgment upon the rebellious, including the false teachers and the heretical mockers in the apostasy.
In verse 7 Peter goes on to say, “But the heavens and the earth now, by the same word, have been reserved for fire, being kept unto the day of judgment and destruction of ungodly men.” In this verse the word “now” is in contrast with “then” in verse 6. It refers to the present heavens and earth, which remain by the word of God (Gen. 8:22), not to be destroyed again by water (Gen. 9:11), but to be burned by fire on the day of judgment and destruction of ungodly men.
In verse 7 Peter speaks of the “same word.” The false and heretical teachings in the apostasy are a deviation from the word of God spoken by the prophets in the Old Testament and the apostles in the New Testament. Hence, the antidote administered by Peter’s inoculation against the poison of the apostate teachings is the holy word with the divine revelation, which he emphasizes repeatedly.
According to Peter’s word, the heavens and the earth “have been reserved for fire.” The word “reserved” means kept in store. The fire here is the fire that will burn up the heavens and the earth (v. 10) at the end of the millennium when the judgment of the great white throne is come (Rev. 20:11). God’s initial judgment upon the universe was by water (2 Pet. 3:6), but His consummate judgment will be by fire. Water only washes away the filthiness from the surface, but fire changes the nature of the entire substance. This indicates further that the heavens and the earth will not remain the same as they are, but will be cleared up by fire, and that the ungodly false teachers and mockers will be judged and destroyed under the divine government.
The judgment in verse 7 denotes the judgment of the great white throne, which will follow the millennium and precede the new heaven and new earth (Rev. 20:11—21:1). Through that judgment all the ungodly will be cast into the lake of fire for destruction. Since it will be the final judgment upon men and demons, it is of the greatest concern to the government of God in the universe.