In Matthew’s account of Jesus’ teaching, the past—the “days of Noah”—shape how disciples are to understand the coming in glory of the Son of Man, that mysterious term Jesus used to refer to himself. People in Noah's day, seeing him building the ark, kept about their business, unaware of the flood that would sweep them away. Only Noah and his family were ready for the day of separation between those saved and those lost.
Jesus speaks of a division that “the Coming” will produce. Of two men working in a field and two women sharing the work of grinding meal, “one will be taken and one left”. It is not clear whether those taken or left are the saved. Only that a division will take place and that some will be ready for it and others not.
The need to be ready is emphasized by the shocking image of Christ's coming like “a thief in the night”. If the owner of a house knew when the thief was coming, he would know when to watch his goods and could safely neglect watching at all other times. But precisely because he does not know the time even in general terms, his only safeguard is to ready at all times. Just so the Christian who is called to await the Son of Man who “is coming at an unexpected hour”.
A happy and holy Advent to all!