So you, too, must keep watch! For you don’t know what day your Lord is coming. Understand this: If a homeowner knew exactly when a burglar was coming, he would keep watch and not permit his house to be broken into. You also must be ready all the time, for the Son of Man will come when least expected. Matthew 24:42-44

Now learn a lesson from the fig tree. When its branches bud and its leaves begin to sprout, you know that summer is near. In the same way, when you see all these things, you can know his return is very near, right at the door. I tell you the truth, this generation will not pass from the scene until all these things take place. Matthew 24:32-34

When the Son of Man returns, it will be like it was in Noah’s day. In those days before the flood, the people were enjoying banquets and parties and weddings right up to the time Noah entered his boat. People didn’t realize what was going to happen until the flood came and swept them all away. That is the way it will be when the Son of Man comes. Matthew 24:37-39

Then the people began to multiply on the earth, and daughters were born. Genesis 6:1 

a. Population explosion

b. A twofold similarity

God observed all this corruption in the world, for everyone on earth was corrupt. Genesis 6:12

i. An increase of sin

But I will confirm my covenant with you. So enter the boat—you and your wife and your sons and their wives. Genesis 6:18

ii. A worldwide judgment 

That very day Noah had gone into the boat with his wife and his sons and their wives. With them in the boat were pairs of every kind of animal. A male and female of each kind entered, just as God had commanded Noah. Then the Lord closed the door behind them. Genesis 7:13,14,16

In those days before the flood, the people were enjoying banquets and parties and weddings right up to the time Noah entered his boat. Matthew 24:38 

c. An attitude of preoccupation

d. Mocking of the truth

And God did not spare the ancient world—except for Noah and the seven others in his family. Noah warned the world of God’s righteous judgment. So God protected Noah when he destroyed the world of ungodly people with a vast flood. 2 Peter 2:5

e. The increase of wickedness and violence

The Lord observed the extent of human wickedness on the earth, and he saw that everything they thought or imagined was consistently and totally evil. So the Lord was sorry he had ever made them and put them on the earth. It broke his heart. Genesis 6:5-6

Sin will be rampant everywhere, and the love of many will grow cold. Matthew 24:12

In the last days there will be very difficult times. For people will love only themselves and their money. They will be boastful and proud, scoffing at God, disobedient to their parents, and ungrateful. They will consider nothing sacred.  They will be unloving and unforgiving; they will slander others and have no self-control. They will be cruel and hate what is good. They will betray their friends, be reckless, be puffed up with pride, and love pleasure rather than God. They will act religious, but they will reject the power that could make them godly. Stay away from people like that! 2

Timothy 3:1-5 

People didn’t realize what was going to happen until the flood came and swept them all away. That is the way it will be when the Son of Man comes. Matthew 24:39

f. A lack of spiritual preparation

Watch out! Don’t let your hearts be dulled by carousing and drunkenness, and by the worries of this life. Don’t let that day catch you unaware, like a trap. For that day will come upon everyone living on the earth. Keep alert at all times. And pray that you might be strong enough to escape these coming horrors and stand before the Son of Man. Luke 21:34-36 

g. Time is running out

So you, too, must keep watch! For you don’t know what day your Lord is coming. Understand this: If a homeowner knew exactly when a burglar was coming, he would keep watch and not permit his house to be broken into. You also must be ready all the time, for the Son of Man will come when least expected. Matthew 24:42-44