Jesus said that it will be like it was in the days of Noah and in the days of Lot. In the days of Noah wickedness was increased. Men still bought, sold, went about their business, married, etc. etc. Life went on. But wickedness abounded. Then disaster, the judgment of God, fell on them all in one day. It was the wicked who were destroyed by the disaster, while the righteous were preserved. It was the wicked who were taken out the world, while the righteous were left in it.
In the days of Lot, wickedness was increased. Sodomy and depravity were the norm and not the exception. I think that is what Jesus is saying: what will be the norm in society will be what God considers evil, wickedness, depravity, and abominations. We are not there yet, but we are really going down that road fast. But men still bought and sold, went about their business, married, etc. Life went on. Then disaster, the judgment of God, fell on them all in one day. It was the wicked who were destroyed by the disaster, while the righteous were preserved. It was the wicked who were taken out of the world, while the righteous were left in it. Remember that Jesus said the MEEK will inherit the earth? Just as Israel inherited Canaan, and not a word failed of all that God had spoken. All came to pass.
About two who were sleeping together, grinding together, or working together, one being taken and the other left: (“men” and “women” were inserted in the text and are not in the Greek. The Greek just says two were sleeping, while one was taken and the other left.) The modern church has taken this to be a reference to the rapture, that the one who is a believer is taken up to heaven, while the one who was left was left to face the disaster, the judgment of God.
Actually this is more than Jesus said. It could just as well mean that the one who was wicked was taken away for judgment, while the one who was righteous was left, as Noah was left in the world, and as Lot was left in the world, when the others were destroyed. We won’t really know which way it will be until the day actually happens.
The main point to take away from this passage is BE READY! LIVE READY! Live every day as if today is THE day, because normal life will go on, and you won’t be able to tell, other than by the wickedness which increases, whether today is the day or not. Whether we are taken and rescued from disaster, or the wicked taken for judgment and we are left, doesn’t matter – the point is, GOD WILL PRESERVE THE RIGHTEOUS OUT OF JUDGMENT! The disasters and judgments aren’t meant for us, so do not be afraid!