From: Matthew 24:42-51
Vigilance. The Faithful Servant
(Jesus said to his disciples,)  "Watch therefore, for you do not know on what day your Lord is coming.  But know this, that if the householder had known in what part of the night the thief was coming, he would have watched and would not have let his house be broken into.  Therefore you also must be ready; for the Son of man is coming at an hour you do not expect.
 "Who then is the faithful and wise servant, whom his master has set over his household, to give them their food at the proper time?  Blessed is that servant whom his master when he comes will find so doing.  Truly, I say to you, he will set him over all his possessions.  But if that wicked servant says to himself, 'My master is delayed,'  and begins to beat his fellow servants, and eats and drinks with the drunken,  the master of that servant will come on a day when he does not expect him and at an hour he does not know,  and will punish him, and put him with the hypocrites; there men will weep and gnash their teeth."
42. Jesus himself draws from this revelation about the future the practical moral that a Christian needs to be on the watch, living each day as if it were his last.
The important thing is not to be speculating about when these events will happen and what form they will take, but to live in such a way that they find us in the state of grace.
51. "And will punish him [or, cut him in pieces]": this can be understood as a metaphor for "will cast him away". "Weeping and gnashing of teeth": the pains of hell.
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.