Well, why would the dead in Christ need to be raised from the dead if they're already in heaven with God??? No one can answer that question
For the Lord himself will come down from heaven, with a loud command, with the voice of the archangel and with the trumpet call of God, and the dead in Christ will rise first.
>they're already in heaven with God?
Where did you get that from? They are not, they are sleeping, meaning unaware of Christ.
They sleep until they become aware or until the Lord of Hosts takes up their cause, whichever comes first. The Lord will send an Angel, none other than Jesus Christ to take up their cause by his power and blood of sacrifice. That will be the case for most humanity because they never learned about self sacrifice and the Christ principle because they have always been asleep, willfully, to that point. Read what I said about John and Elijah.