Paul indicated that the dead are raised at the same time the living are glorified--it is all a single event associated with the 2nd Coming on the Last Day.
You are referring to 1 Thes 4:13-18.
Read it carefully knowing that in Revelation 20:4-6 it says that only the dead martyrs are raised first. These people are known as the "Dead in Christ" or "those who sleep in Him". No other person is raised.
13 But I do not want you to be ignorant, brethren, concerning those who have fallen asleep, lest you sorrow as others who have no hope. 14 For if we believe that Jesus died and rose again, even so God will bring with Him those who sleep in Jesus.
15 For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep. 16 For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first. 17 Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord. 18 Therefore comfort one another with these words.
1 Thes 4:13-18 Explained
"But I do not want you to be ignorant, brethren, concerning those who have fallen asleep, lest you sorrow as others who have no hope. For if we believe that Jesus died and rose again, even so God will bring with Him those who sleep in Jesus." Verse 13-14
Verses 13 and 14 say that people should not grieve for the dead believers, and that the dead believers will be raised and return with Him. The wording at the end of verse 14 says that those who return with Him are the ones that fell asleep in Christ. This would be the martyrs as mentioned in
Revelation 20:4. If this is the martyrs, then they come and reign for 1000 years with Christ. This is not the last day.
"For this we say to you by the word of the Lord, that we who are alive and remain until the coming of the Lord will by no means precede those who are asleep." Verses 15
Then, verse 15 is simply saying that we who are alive right now should not expect to be raised until the martyrs have been raised first. We will not proceed them. The dead in Christ who are the martyrs are raised first, and reign with Christ for 1000 years, then on the last day, we who are left alive at that time will be raised also. This final raising of people would be all who are alive. Both believer and non-believer as well as those who are alive and those who are in the grave.
"For the Lord Himself will descend from heaven with a shout, with the voice of an archangel, and with the trumpet of God. And the dead in Christ will rise first." Verse 16
This is going into more detail about when Jesus returns with the martyrs. There will be a shout from an archangel and a trumpet sound. And the martyrs will be raised in the first resurrection.
"Then we who are alive and remain shall be caught up together with them in the clouds to meet the Lord in the air. And thus we shall always be with the Lord." Verse 17
This is the last day. We who are here on the very last day will be raised up in the twinkling of an eye (
1 Cor 15:51-52) to go to judgment. Believers will then be with the Lord forever, while others will be condemned.
If Revelation 20:4-6 says that it is only the Martyrs who are raised and return with Christ and no other believer, but our own viewpoint contradicts this, then it is not scripture that has the issue. It would be our faulty eschatology.
So, once again, try reading 1 Thes 4:15-18 with the view that those who return are the martyrs. The rest of us are raised on the last day just as Jesus said 6 times.