Matthew 24:43

“But know this, that if the master of the house had known in what watch the thief was coming, he would have watched, and would not have allowed his house to be broken through.”

Here the master of the house has clearly returned to his house and discovered that the wall has been broken through. But if only he had know at what time the thief was coming he would have remained at home and prevented it. The point, however, is that he did not know. Thus his only hope was to watch all the time. And because he had failed to do that the burglary had taken place. His problem therefore was that he had failed to watch all the time. The inference to be gathered is that we have to be on the watch all the time so that nothing can break in and spoil our lives.