OK..let's look at that scripture and what precedes it.....what is the "rapture" and who experiences it?
1 Thessalonians 4:13-18....."We do not want you to be uninformed, brothers, concerning those who are asleep, so that you will not grieve like the rest, who have no hope. Since we believe that Jesus died and rose again, in the same way God will bring with Him those who have fallen asleep through Jesus. For we say this to you by a revelation from the Lord: We who are still alive at the Lord’s coming will certainly have no advantage over those who have fallen asleep. For the Lord Himself will descend from heaven with a shout, with the archangel’s voice, and with the trumpet of God, and the dead in Christ will rise first. Then we who are still alive will be caught up together with them in the clouds to meet the Lord in the air and so we will always be with the Lord. Therefore encourage one another with these words." (Holman)
So Paul starts off by talking about those who "sleep" in death (these are all still in their graves) ....that they will not be grieved in the same way as those without hope grieve over their loved ones. Then he speaks of the resurrection, noting that those "who are still alive at the Lord’s coming will certainly have no advantage over those who have fallen asleep". Why? Because "the Lord Himself will descend from heaven with a shout, with the archangel’s voice, and with the trumpet of God, and the dead in Christ will rise first." When does this take place? When the Lord returns, then those called to heaven "will rise first". This harmonizes with Rev 20:6 where those chosen to be "kings and priests" to rule with Christ in his kingdom, will experience the "first resurrection". If there is a "first"...there is another to come.
If there are kings, then there are subjects...if there are priests, then there are sinners who need their intercession.
So those who "sleep in death" are not raised until Jesus returns. The "sign" Jesus gave to indicate his return is recorded in Matt 24:3-14. There is no need of a "sign" if the return of Christ is a visible event. Daniel saw a vision of Christ's enthronement in heaven at the time when the "last days" or "the time of the end" began. It was unseen to human eyes, but indicated by world events.
The First World War was the beginning of the sign and the others followed in rapid succession. This is the time Christ returned and began the greatest preaching campaign in the history of the world.
A "great tribulation" was foretold which would be worse than anything mankind has ever experienced before....or would ever experience again (Matt 24:21)...this will be at the very end of these last days, when the bride of Christ becomes complete in order for the marriage of the Lamb to take place in heaven.
"Soon the angels will unleash the destructive winds of the great tribulation. This will occur after all the remaining ones of Christ’s "brothers" left on earth have received their final sealing. (Rev. 7:1-3)
Before Armageddon breaks out, anointed ones will be taken to heaven. (Matt. 13:41-43) Therefore, now is the time for those who hope to be judged as sheep to support Christ’s brothers loyally.”