God Warns Us About What Is Coming
Time: During Construction of the Ark
It took over 100 years to build the ark? Why so long? Because God was using Noah, and the construction of the ark (which was sure to attract attention) to warn people about what was coming. God does this throughout history. In the book of Jonah God sends Jonah to the city of Nineveh to warn the people there they are about to be destroyed, if they do not turn away from their wicked ways. The people of Nineveh did turn away from evil and to God, and they were saved. But in Noah's day no one listened to him.
"For if God did not spare angels when they sinned, but cast them into hell and committed them to pits of darkness, reserved for judgment; and did not spare the ancient world, but preserved Noah, a preacher of righteousness, with seven others, when He brought a flood upon the world of the ungodly; and if He condemned the cities of Sodom and Gomorrah to destruction by reducing them to ashes, having made them an example to those who would live ungodly lives thereafter; and if He rescued righteous Lot, oppressed by the sensual conduct of unprincipled men (for by what he saw and heard that righteous man, while living among them, felt his righteous soul tormented day after day by their lawless deeds), then the Lord knows how to rescue the godly from [b]temptation, and to keep the unrighteous under punishment for the day of judgment, and especially those who indulge the flesh in its corrupt desires and despise authority." - 2 Peter 2:4-10
Yes, those who disobey God will be destroyed to experience external punishment. And those who trust God to save them. Who turn away from disobedience and turn to God, will be saved.
Jesus speaking: "For the coming of the Son of Man [Jesus] will be just like the days of Noah. For as in those days before the flood they were eating and drinking, marrying and giving in marriage, until the day that Noah entered the ark, and they did not understand until the flood came and took them all away; so will the coming of the Son of Man be. " - Matthew 24:37-39
First notice that Jesus speaks of the flood as a real event. To deny the global flood is to call Jesus a liar. Second, only those who listened to God's warnings, and got on the ark, were saved.
Jesus speaking: "And just as it happened in the days of Noah, so it will be also in the days of the Son of Man:" [Jesus] "they were eating, they were drinking, they were marrying, they were being given in marriage, until the day that Noah entered the ark, and the flood came and destroyed them all. It was the same as happened in the days of Lot: they were eating, they were drinking, they were buying, they were selling, they were planting, they were building; but on the day that Lot went out from Sodom it rained fire and brimstone from heaven and destroyed them all. It will be just the same on the day that the Son of Man is revealed." - Luke 17:26-30
Next: The Door
Go Deeper: 2nd Peter