2 Peter 3:1-9 (ESV)
The Day of the Lord Will Come
3:1 This is now the second letter that I am writing to you, beloved. In both of them I am stirring up your sincere mind by way of reminder, 2 that you should remember the predictions of the holy prophets and the commandment of the Lord and Savior through your apostles, 3 knowing this first of all, that scoffers will come in the last days with scoffing, following their own sinful desires. 4 They will say, “Where is the promise of his coming? For ever since the fathers fell asleep, all things are continuing as they were from the beginning of creation.” 5 For they deliberately overlook this fact, that the heavens existed long ago, and the earth was formed out of water and through water by the word of God, 6 and that by means of these the world that then existed was deluged with water and perished. 7 But by the same word the heavens and earth that now exist are stored up for fire, being kept until the day of judgment and destruction of the ungodly.
8 But do not overlook this one fact, beloved, that with the Lord one day is as a thousand years, and a thousand years as one day. 9 The Lord is not slow to fulfill his promise as some count slowness, but is patient toward you,  not wishing that any should perish, but that all should reach repentance.