Matthew 24:39-44

and they did not understand until the flood came and took them all away; so will the coming of the Son of Man be. Then there will be two men in the field; one will be taken and one will be left. Two women will be grinding at the mill; one will be taken and one will be left. “Therefore be on the alert, for you do not know which day your Lord is coming. But be sure of this, that if the head of the house had known at what time of the night the thief was coming, he would have been on the alert and would not have allowed his house to be broken into. For this reason you also must be ready; for the Son of Man is coming at an hour when you do not think He will.