Were the “sleeping saints” already in heaven?
“We believe that Jesus died and rose again and so we believe that God will bring with Jesus those who have fallen asleep in him. According to the Lord’s own word, we tell you that we who are still alive, who are left till the coming of the Lord, will not precede those who have fallen asleep. For the Lord himself will come down from heaven, with a shout and a command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first. After that, we who are still alive and are left will be caught up together with them in the clouds to meet the Lord in the air. And so we will be with the Lord forever.” 1 Thessalonians 4:14-17
We believe that Verse 14 refers to the first act of Jesus when he returned in 1874, which was to resurrect the sleeping saints (the apostles as well as all faithful Christians who died in Christ prior to his return). The phraseology “God will bring with Jesus” means that God will bring BACK with Jesus those who have “fallen asleep in him.”
Verse 16 attests to this interpretation when it says that Jesus himself will command with the trumpet call of God that the dead in Christ rise first. (These are the same sleeping saints mentioned in Verse 14.)
How could these saints be resurrected when Jesus returned if they were already in heaven with him?
There would have been no purpose for Jesus to command them to rise. Verse 17 ends by telling what will happen when physical death occurs to faithful Christians living now at the end or harvest of this time of the church.
Verse 17 says that future saints now living “will be caught up [changed at the moment of death] together with them [to be like the saints who were already raised at Jesus’ second presence, mentioned in Verse 14] in the clouds to meet the Lord in the air [the earth’s atmosphere, not the heaven of heavens].”
To learn more about Jesus’ return listen to, “Could Jesus Return Without You Knowing?”