What does Matthew 24:40 mean?

Interpreters of different traditions have come to drastically different conclusions about what Jesus means in this passage. Some of those possibilities are more reasonable than others. It is most helpful to pay attention to the context of this and the following verses.

Jesus has been describing how sudden and unexpected Noah's flood was for those living during that time (Matthew 24:37–39). They were going about their daily lives with no awareness of God's coming judgment until the flood waters came and wiped them from the face of the earth. Christ's return to earth as the judge and king (Revelation 19:11–15) will be similar. Everyone will be going about their business with no clue of when His arrival will happen or what it will mean for them.

In that context, it seems most likely that Jesus is saying some will be taken away in judgment—through death in the catastrophes of the end times (Matthew 24:21–22, 29)—while others survive to continue to live on earth under His protection and blessing (Revelation 20:1–6). The other possibility reaches back to Jesus sending out His angels to gather His elect from earth (Matthew 24:31). Some teachers believe the one taken is part of the elect: a true believer in Christ chosen by God, who is "taken" in the sense that he is gathered off the earth and to Christ.

For that reason, some believe Jesus is describing what is commonly called the rapture of the church (1 Thessalonians 4:16–17). In looking at this passage, some suggest this rapture will happen after the tribulation period. Those who believe in a pre- or mid-tribulation rapture would understand those taken in this passage to be taken in judgment by Christ.