Jesus said in Matthew 24:43 "But understand this: If the owner of the house had known at what time of NIGHT the thief was coming, he would have kept watch and would not have let his house be broken into." Precisely we know the "thief" will come at "night" and not in the morning or the afternoon. So its very imperative that we must keep watch and stay pure during this season of time. God knows some or many of his children will fall into "sleep", that is why Jesus forewarn us to keep watch and get ready for the "thief". Jesus said in Matthew 24:25: "See, I have told you ahead of time."