Here's the passage as it stands. It is taken from Jesus' "eschatological discourse" in Matthew 24:
As were the days of Noah, so will be the coming of the Son of man. 38 For as in those days before the flood they were eating and drinking, marrying and giving in marriage, until the day when Noah entered the ark, 39 and they did not know until the flood came and swept them all away, so will be the coming of the Son of man. 40 Then two men will be in the field; one is taken and one is left. 41 Two women will be grinding at the mill; one is taken and one is left. 42 Watch therefore, for you do not know on what day your Lord is coming (Matt 24:37-42).Now, according to the standard rapturist interpretation, when Jesus says, "one is taken and one is left," he is teaching that the righteous one will be "raptured" while the wicked, unbelieving heathens will be "left behind."
The problem with this view however is that it seems contradict what Jesus is actually saying.
The larger context of the passage is an analogy: Jesus is describing the time of the coming of the Son of man in terms of the flood judgment.
What is often missed is this: according to Jesus, in the days of Noah it was the wicked who were "swept away" (Matt 24:39). In other words, in the days of Noah, the wicked were the ones taken.
Hence, it would seem that in Jesus' analogy, it is desirable to be among those left behind--i.e., those not swept away as the wicked were in the days of Noah. A careful reading then would suggest that the righteous are those who are left behind, not those taken.
I realize that the view that Jesus here links salvation with those being "taken" is very much entrenched, no doubt in part due to the influence of the rapture interpretation. Yet such a reading does not seem to flow naturally from the text. In fact, such a reading in fact reverses the imagery so that the days of the Son of man are unlike the days of Noah, contrary to what Jesus himself seems to teach.
So much for worrying about being "left behind."