In 1 Thessalonians 4:14 Paul tells us that the people that He refers to as "sleeping" will rise from the dead just like Jesus.
1Th 4:14 For if we believe that Jesus died and rose again, even so, them also which sleep in Jesus will God bring with him.
Jesus both died and was resurrected on earth.
Meaning that Paul was speaking here about the earthly resurrection that He referred to in Romans 6:13.
Meaning that the "sleepers" are backslidden believers.
Rm 6:13 Neither yield ye your members as instruments of unrighteousness unto sin: but yield yourselves unto God, as those that are alive from the dead, and your members as instruments of righteousness unto God.
I am curious to find out how rapturists deal with this.