Peter gives a powerful example of God's intervention and judgment, but notice that it is prefaced with the statement that these people were willfully forgetting what the Bible teaches. He is not describing atheists or people who are totally unfamiliar with Scripture. In verse 4, these people mention the creation, not evolution. They know what is written, yet they choose to ignore or undermine the truth.
If they would acknowledge the biblical accounts as true and meaningful, it would remind them that there is a God to whom they are accountable—which would interfere with their lives. So they perform this mental evasion so they do not have to consider what God thinks of them. However, Romans 1:20-21 says mankind is without excuse. Whether or not a person has been called, ample evidence exists to convict him of God's existence and standards.
Peter draws attention to the creation and the earth being formed, as well as to a great flood that caused a previous world to perish. This description could apply to a couple of different events. It is usually taken to refer to the Flood of Noah, which certainly fits. The pre-Flood world is completely gone.
However, the world before the Flood was not the original world. In Genesis 1:1, God creates the heavens and the earth, yet by verse 2, something has happened to cause the earth to become “without form, and void.” The earth is covered with water (verses 2, 6, 9). So God re-creates the heavens and the earth, creates man, and later re-creates the world destroyed in Noah's Flood.
In reading about the re-creation, it appears that the original world—the first estate of the angels—also perished in a flood. So the world that perished in II Peter 3:6 could have been the re-created world, but it also could have been the original world, the one destroyed when the archangel Hêlêl and his followers left their proper domain (Jude 6).
Regardless of which creation and destruction Peter refers to, the fact remains that it was by God's Word—by His spoken command—that both worlds came into existence, and by His judgment both worlds were flooded with water. The same Creator God is now upholding all things by the word of His power (Hebrews 1:3).
However, the heavens and earth of our time are being reserved for a future judgment of fire instead of water. Another judgment is coming, and the ungodly will face destruction. We understand this, but we should also recognize that the warning about scoffers is here because it is possible to lose our present understanding and godly fear. If we allow our natural desires to gain the upper hand and overrule our faith as the driving force in our lives, then the return of Jesus Christ and the future judgment will seem like a fable to us, too. The words of the prophets and apostles will lose their gravity, and our focus will be on simply living for the moment.