And here is some pertinent scripture:
Matthew 24:37-41
37 As it was in the days of Noah, so it will be at the coming of the Son of Man. 38 For in the days before the flood, people were eating and drinking, marrying and giving in marriage, up to the day Noah entered the ark; 39 and they knew nothing about what would happen until the flood came and took them all away. That is how it will be at the coming of the Son of Man. 40 Two men will be in the field; one will be taken and the other left. 41 Two women will be grinding with a hand mill; one will be taken and the other left.
It's perfectly clear that those who will be taken will die; swept away as those in the flood were swept away. It's the ones remaining who will survive.
If you can get them to read these verses and think about what they say, maybe the true meaning will sink in. You might also argue that Rapture theology didn't exist in Christianity until about 1830. Could Christianity have been wrong about this for 1,830 years?