Jesus told his disciples that without warning he would return and judge people.

Luke 17:22-37

22 Jesus said to his disciples, “There will be a time when you will want to see me [MTY], the one who came from heaven, ruling powerfully. But you will not see that. 23 Some people will say to you, ‘Look, the Messiah is over there!’ or they will say ‘Look, he is here!’ When they say that, do not believe them. Do not follow them to go see the Messiah. 24 Because when the lightning flashes and lights up the sky from one side to the other, everyone can see it. Similarly [SIM], at the time [MTY] when I, the one who came from heaven, come back again, everyone will see me. 25 But before that happens, I must suffer in many ways (OR, very much). And I will be rejected by people {people will reject me}, even though they have observed me doing good for people. 26 But when I, the one who came from heaven, come again, people will be doing things just like people were doing at the time when [MTY] Noah lived. 27 At that time people ate and drank as usual, and they got married as usual, up until the day when Noah and his family entered the big boat. But then the flood came and destroyed all those who were not in the boat. 28 Similarly, when Lot lived in Sodom city, people there ate and drank as usual. They bought things and they sold things. They planted crops and they built houses as usual. 29 But on the day that Lot and his family left Sodom, fire and burning sulfur came down from the sky and destroyed all those who stayed in the city. 30 Similarly, when I, the one who came from heaven, return to earth, people will be unprepared (OR, enjoying normal life). 31 On that day, those who are outside their houses, with all the things that they own inside the houses, must not go in to take them away, because there will not be enough time to do that. Similarly, those who are working in a field must not go back home to get anything; they must flee immediately. 32 Remember Lot’s wife! Because she turned back and wanted to get some of her things from Sodom, she died immediately and became a pillar of salt. 33 Anyone who wants to hold onto his life and his possessions will not receive eternal life. But anyone who is willing to die for my sake will live eternally. 34 I tell you this: On the night when I return, there will be two people sleeping in one bed. The one who believes in me will be taken {God will take the one who believes in me} to heaven, and the other one will be left behind and punished {and he will leave the other one behind and punish him}. 35-36 35-36Two women will be grinding grain together; one will be taken and the other left {God will take one and leave the other} behind.” 37 His disciples said to him, “Lord, where will this happen?” He replied to them, “Wherever there is an animal carcass, the vultures will gather to eat it [MET]. Similarly, wherever there are people who are spiritually dead, God will punish them.”