But no  man, nay, not even the angels of heaven, knew when these things would occur.  Since it would come as a surprise to those heavenly beings, then little wonder that it should come as a great shock and terror to those dwelling upon the earth.  Like the flood in the days of Noah, it would descend of a sudden and sweep them away.  And, surely, the Jews were not ready for the terrible destruction that was to be visited upon them by the armies of Titus.  The Romans fell upon the land with great vengeance, taking some and leaving others.  Likewise shall it be when Christ returns in glory to bring an end to history, and summon all the legions of mankind to His judgment bar.  The world will not be looking for Him, will not be expecting Him, but come He will, to the great terror and consternation of the wicked.  Therefore He enjoins us in verse 42, “Watch therefore: for ye know not what hour your Lord doth come.”

He gives us an analogy to drive home the point, that of a householder whose home is broken up by a thief.  Had he known when the thief would come, he would have been ready and waiting.  But, because he was unaware the thief was lurking, his house is plundered.  So it is with the man who is not prepared to Christ’s coming.  Unprepared, he is surprised and devastated when the trumpet sounds, the clouds are rolled back like a scroll, and the Lord descends with ten thousands of His saints and all the holy angels.  The message, then, is clear: We must prepare for Christ’s return by holy living and sober watchfulness.