3 Dear friends, this is now my second letter to you. I have written both of them as reminders to stimulate you to wholesome thinking. 2 I want you to recall the words spoken in the past by the holy prophets and the command given by our Lord and Savior through your apostles. 3 Above all, you must understand that in the last days scoffers will come, scoffing and following their own evil desires. 4 They will say, “Where is this ‘coming’ he promised? Ever since our ancestors died, everything goes on as it has since the beginning of creation.” 5 But they deliberately forget that long ago by God’s word the heavens came into being and the earth was formed out of water and by water. 6 By these waters also the world of that time was deluged and destroyed. 7 By the same word the present heavens and earth are reserved for fire, being kept for the day of judgment and destruction of the ungodly.
As Peter goes to finish he letter his friends, he addresses the second coming of Jesus. There were some who were saying that since Jesus hasn't returned yet, maybe he wouldn't really come back. To take it one step further they used it as an excuse to sin. They use the phrase "ever since our ancestors. They were now the second generation of Christians which is why some date this letter late 1st century. Regardless, their wishful thinking has left them in a dangerous situation.
Peter reminds them that the same God who spoke Creation into existence by His Word through water. Also, through the same Word, all but Noah and his family were destroyed by the flood. Therefore, Peter reminds them that by this same Word the heavens and earth will be destroyed by fire. Though they may not be present when Jesus returns, they still will be accountable for their actions.
Importantly, Peter wants to warn the believers not to buy into these lies by these so called "scoffers". They are living in the short term and not weighing the consequences of living only for today. But, before we get too judgmental about these scoffers, I wonder if we more subtly do the same thing. Is there part of us that thinks, "Well Jesus has come back in a long time, it might as well not worry about it." Since we don't know we should ready any day.