With the use of the word “thief” Jesus reminds his hearers of his earlier declaration that he was coming as a thief (Matthew 24:42–44; Luke 12:39–40). Success for the thief depends on the element of surprise—a reality that implies that Jesus will give no warning as to his imminent return. That does not mean, of course, that there are no warning signs. Jesus himself had once said that his coming would be like the days of Noah. Noah’s generation saw the ark slowly taking shape, heard Noah’s words of warning over the span of many years, and even witnessed the animals' entering the ark. They could have known a flood was coming, but they chose to ignore the warnings so that the rain yet caught them unprepared (Matthew 24:36–39), like some people just don’t bother to lock their doors when out. They have, in other words, a false sense of security.
15 (“Behold, I am coming like a thief! Blessed is the one who stays awake, keeping his garments on, that he may not go about naked and be seen exposed!”)