First, let's look at what Jesus taught will happen on the day He returns.
Matthew 24:35 Heaven and earth shall pass away, but my words shall not pass away. 36 But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only. 37 But as the days of Noah were, so shall also the coming of the Son of man be. 38 For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark, 39 And knew not until the flood came, and took them all away; so shall also the coming of the Son of man be.
First, Jesus points out here that "heaven and earth shall pass away and "of that day and hour knoweth no man, no, not the angels of heaven, but my Father only". So, He taught that heaven and earth will pass away unexpectedly. Then He pointed out that the flood "took them all away" ("destroyed them all" - Luke 17:27) after Noah entered the ark and He said in relation to that "so shall also the coming of the Son of man be" ("Even thus shall it be in the day when the Son of man is revealed". - Luke 17:30).
Peter also taught that heaven and earth will pass away unexpectedly and will destroy all unbelievers on the day Jesus returns.
2 Peter 3:3 Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, 4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation. 5 For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water: 6 Whereby the world that then was, being overflowed with water, perished: 7 But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men. 8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day. 9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. 10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. 11 Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, 12 Looking for and hasting unto the coming of the day of God, wherein the heavens being on fire shall be dissolved, and the elements shall melt with fervent heat? 13 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness.
We know that Peter is talking about something relating to the day of Christ's return in 2 Peter 3:6-7 and 2 Peter 3:10-13 because the context of what he is talking about is established in verses 3 and 4 where he points out that scoffers scoff at the promise of His second coming. Their scoffing will be put to an end once and for all when Jesus returns to "destroy them all" like happened with the flood in Noah's day except this time they will all be destroyed by fire.
No one knows the day or hour Jesus will come as a thief in the night to burn up and renew the heavens and the earth by fire, resulting in the "new heavens and a new earth, wherein dwelleth righteousness". That's why Peter said "Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, Looking for and hasting unto the coming of the day of God". Knowing that the day will come when Jesus takes vengeance on all of His enemies, we need to examine ourselves and make sure that we are ready for that day. As Paul said about that same day, "But ye, brethren, are not in darkness, that that day should overtake you as a thief. Ye are all the children of light, and the children of the day: we are not of the night, nor of darkness. Therefore let us not sleep, as do others; but let us watch and be sober (1 Thessalonians 5:4-6).
Matthew 24:35 Heaven and earth shall pass away, but my words shall not pass away. 36 But of that day and hour knoweth no man, no, not the angels of heaven, but my Father only. 37 But as the days of Noah were, so shall also the coming of the Son of man be. 38 For as in the days that were before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noe entered into the ark, 39 And knew not until the flood came, and took them all away; so shall also the coming of the Son of man be.
First, Jesus points out here that "heaven and earth shall pass away and "of that day and hour knoweth no man, no, not the angels of heaven, but my Father only". So, He taught that heaven and earth will pass away unexpectedly. Then He pointed out that the flood "took them all away" ("destroyed them all" - Luke 17:27) after Noah entered the ark and He said in relation to that "so shall also the coming of the Son of man be" ("Even thus shall it be in the day when the Son of man is revealed". - Luke 17:30).
Peter also taught that heaven and earth will pass away unexpectedly and will destroy all unbelievers on the day Jesus returns.
2 Peter 3:3 Knowing this first, that there shall come in the last days scoffers, walking after their own lusts, 4 And saying, Where is the promise of his coming? for since the fathers fell asleep, all things continue as they were from the beginning of the creation. 5 For this they willingly are ignorant of, that by the word of God the heavens were of old, and the earth standing out of the water and in the water: 6 Whereby the world that then was, being overflowed with water, perished: 7 But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men. 8 But, beloved, be not ignorant of this one thing, that one day is with the Lord as a thousand years, and a thousand years as one day. 9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. 10 But the day of the Lord will come as a thief in the night; in the which the heavens shall pass away with a great noise, and the elements shall melt with fervent heat, the earth also and the works that are therein shall be burned up. 11 Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, 12 Looking for and hasting unto the coming of the day of God, wherein the heavens being on fire shall be dissolved, and the elements shall melt with fervent heat? 13 Nevertheless we, according to his promise, look for new heavens and a new earth, wherein dwelleth righteousness.
We know that Peter is talking about something relating to the day of Christ's return in 2 Peter 3:6-7 and 2 Peter 3:10-13 because the context of what he is talking about is established in verses 3 and 4 where he points out that scoffers scoff at the promise of His second coming. Their scoffing will be put to an end once and for all when Jesus returns to "destroy them all" like happened with the flood in Noah's day except this time they will all be destroyed by fire.
No one knows the day or hour Jesus will come as a thief in the night to burn up and renew the heavens and the earth by fire, resulting in the "new heavens and a new earth, wherein dwelleth righteousness". That's why Peter said "Seeing then that all these things shall be dissolved, what manner of persons ought ye to be in all holy conversation and godliness, Looking for and hasting unto the coming of the day of God". Knowing that the day will come when Jesus takes vengeance on all of His enemies, we need to examine ourselves and make sure that we are ready for that day. As Paul said about that same day, "But ye, brethren, are not in darkness, that that day should overtake you as a thief. Ye are all the children of light, and the children of the day: we are not of the night, nor of darkness. Therefore let us not sleep, as do others; but let us watch and be sober (1 Thessalonians 5:4-6).