Some of the commentaries I’ve looked at have flipped the popular-media images of the rapture completely around, suggesting that those taken are taken to judgment, and those “left behind” are actually being spared. This would be similar to those swept away by the flood, as suggested by the comparison made in this passage.
Regarding the verses on Noah’s Day, Sherman E. Johnson states in The Interpreter’s Bible,
“There was nothing wrong in their eating and drinking and their other lawful pursuits. What was wrong was that they were heedless and entirely immersed in ordinary occupations.”
In his commentary, Brian P. Stoffregen states,
“In contrast to the terrible and great signs of the end that no one could miss -- and without God's help believers could not endure (24:22), our text indicates that the time of the end will be quite peaceful and normal. People will: be eating and drinking, marrying and giving in marriage, and working at home or business. In the everyday-ness of this life, it might be easy to forget about the "coming of the Son of Man."
Stoffregen also points out that much of the text has to do with prioritizing—what are we most concerned about? When the time comes, will we be ready? How do we become ready or prepare?
"In contrast to the long, commercial buildup and advertising about the shopping
days until Christmas, our text clearly indicates that we do not know when the
day and hour of the Coming will come. Perhaps a reference could be made back to
the Garden of Eden -- the humans sin by trying to know more than God intended
them to know.”
In The Interpreter’s Bible, George A. Buttrick echoes Stoffregen's sentiment:
“We must be faithful to our human ignorance about all things, and especially
about ‘last things.’ How little we know! Our political and economic wisdom is
again and again confounded by events.”
Therefore, it seems we cannot be the small children cramming all our good behavior into a few days or weeks to please Santa before Christmas. We must be ready at all times, and somehow carry out the tasks of daily living without becoming preoccupied or ruled by them.