Not that I’m at all a believer in the rapture, but the verse I always associated with it was Luke 17:34–37:

34 I tell you, on that night two people will be in one bed; one will be taken and the other left. 35 Two women will be grinding grain together; one will be taken and the other left.” 37 “Where, Lord?” they asked. He replied, “Where there is a dead body, there the vultures will gather.”