Scripture tells us that all that are in the graves will hear the trumpet. It doesnt mention heaven here at all. Also, when scripture says that the dead are "sleeping" or "sleeping in Christ', they are still dead. It is symbollic because "like a sleep" they will awake from "death" at his return. When your dead, you are dead until the resurrection. Here are some verses that prove that.
1. "Dust thou art: to dust thou shalt return." (Genesis 3:192. "Abraham gave up the "spirit" (gava: expired, breathed out), and died, and was gathered to his people"3. "In death there is no remembrance of Thee: in the grave, who shall give Thee thanks?" (Psalm 6:5).4. "The dead praise not the LORD, neither any that go down into silence." (Psalm 115:17)
5. "The grave cannot praise Thee; death cannot celebrate Thee; they that go down into the pit cannot hope for Thy truth: the living, he shall praise Thee, as I do this day" (Isaiah 38:18-19).
6. "For the living know that they shall die: but the dead know not any thing, neither have they any more a reward; for the memory of them is forgotten. 6Also their love, and their hatred, and their envy, is now perished; neither have they any more a portion for ever in any thing that is done under the sun."
7. "Wherefore, as by one man sin entered into the world, and death by sin; and so death passed upon all men, for that all have sinned." Romans 5:12
These are just some verses that tell us what happens in death. God says that we will die. Why would you not want to believe that? If you fear God, you dont fear death. Paul say that we have hope in the resurrection.
These verses tell us that we CANNOT praise God. We dont have any more memory of anything. We dont think, love, hate, envy, etc. We are dead, until the return of Christ.