If the dead go to heaven or hell, who is God going to resurrect?

Everyone who is dead gets resurrected after the millennial kingdom.


Revelation 20:4-5 KJV
[4] And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years. [5] But the rest of the dead lived not again until the thousand years were finished. This is the first resurrection.

There is NO RELIGION higher than Truth.

Proverbs 12:19

The lip of truth shall be established for ever: but a lying tongue is but for a moment.

Isaiah 25:1 KJV

O Lord, thou art my God; I will exalt thee, I will praise thy name; for thou hast done wonderful things;

thy counsels of old are faithfulness and truth.

Strange how truth is the least popular 'religion' isn't it?
As Jesus said;
"YOU worship what YOU do not know; we worship what we know, because salvation originates with the Jews. 23 Nevertheless, the hour is coming, and it is now, when the true worshipers will worship the Father with spirit and truth, for, indeed, the Father is looking for suchlike ones to worship him. 24 God is a Spirit, and those worshiping him must worship with spirit and truth.” 25 The woman said to him: “I know that Mes·si′ah is coming, who is called Christ. Whenever that one arrives, he will declare all things to us openly.” 26 Jesus said to her: “I who am speaking to you am he.” Jo4:23

Obviously, without the great white throne judgment no one would be going to hell. That said we go to places to await this until Jesus returns and some will be "asleep" for the thousand year part of His return. Lazarus makes evident that there exists a gulf wherein some are on one side and others on another for a time. The "rich man" saw him with Abraham and desired to return to this dimension to warn his brothers but was rebuked.

Is that literal or was Jesus speaking a parable?
"I, even I, have said in my heart with regard to the sons of mankind that the [true] God is going to select them, that they may see that they themselves are beasts. 19 For there is an eventuality as respects the sons of mankind and an eventuality as respects the beast, and they have the same eventuality. As the one dies, so the other dies; and they all have but one spirit, so that there is no superiority of the man over the beast, for everything is vanity. 20 All are going to one place. They have all come to be from the dust, and they are all returning to the dust. 21 Who is there knowing the spirit of the sons of mankind, whether it is ascending upward; and the spirit of the beast, whether it is descending downward to the earth? 22 And I have seen that there is nothing better than that the man should rejoice in his works, for that is his portion; because who will bring him in to look on what is going to be after him?' Ecc3:18

Good expression, truth is not very popular however for two reasons. It requires accurate knowledge with accountability and being free there's no money in it for those who capitalize on religion for sale on Sunday.
"YOU worship what YOU do not know; we worship what we know, because salvation originates with the Jews. 23 Nevertheless, the hour is coming, and it is now, when the true worshipers will worship the Father with spirit and truth, for, indeed, the Father is looking for suchlike ones to worship him. 24 God is a Spirit, and those worshiping him must worship with spirit and truth.” 25 The woman said to him: “I know that Mes·si′ah is coming, who is called Christ. Whenever that one arrives, he will declare all things to us openly.” 26 Jesus said to her: “I who am speaking to you am he.” Jo4:22

"For to God we are a sweet odor of Christ among those who are being saved and among those who are perishing; 16 to the latter ones an odor issuing from death to death, to the former ones an odor issuing from life to life. And who is adequately qualified for these things? 17 [We are;] for we are not peddlers of the word of God as many men are, but as out of sincerity, yes, as sent from God, under God’s view, in company with Christ, we are speaking." 2Cor2:15

Right.
"And to Adam he said: “Because you listened to your wife’s voice and took to eating from the tree concerning which I gave you this command, ‘You must not eat from it,’ cursed is the ground on your account. In pain you will eat its produce all the days of your life. 18 And thorns and thistles it will grow for you, and you must eat the vegetation of the field. 19 In the sweat of your face you will eat bread until you return to the ground, for out of it you were taken. For dust you are and to dust you will return.” Ge3:17

The great reformer, Martin Luther, who left
the Roman Catholic Church over its un-Biblical
false doctrines believed in a type of soul sleep.
That is what the Bible teaches... that the dead
are asleep - unconscious until the resurrection.


.

Right, Jesus used sleep as a medafor for death.
"For as respects whoever is joined to all the living there exists confidence, because a live dog is better off than a dead lion. 5 For the living are conscious that they will die; but as for the dead, they are conscious of nothing at all, neither do they anymore have wages, because the remembrance of them has been forgotten. 6 Also, their love and their hate and their jealousy have already perished, and they have no portion anymore to time indefinite in anything that has to be done under the sun." Ecc9;5

The New Testament also teaches the only hope of immortality
is in the resurrection of the dead and Jesus Christ is the
firstfruits of them who sleep in death.


" Christ has indeed been raised from the dead,
the firstfruits of those who have fallen asleep. "

1 Corinthians 15:20


**


" Brothers and sisters, we do not want you to
be uninformed about those who sleep in death,
so that you do not grieve like the rest of mankind,
who have no hope.

For 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. "

1 Thessalonians 4:13-14


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Immortality is only granted to those resurrected to serve as assistant kings with Jesus. This happens in two ways, the first resurrection Rv20, and in current time the remaining remnant of the heavenly class are transferred to heaven when they die
"However, this I say, brothers, that flesh and blood cannot inherit God’s kingdom, neither does corruption inherit incorruption. 51 Look! I tell YOU a sacred secret: We shall not all fall asleep [in death], but we shall all be changed, 52 in a moment, in the twinkling of an eye, during the last trumpet. For the trumpet will sound, and the dead will be raised up incorruptible, and we shall be changed. 53 For this which is corruptible must put on incorruption, and this which is mortal must put on immortality. 54 But when [this which is corruptible puts on incorruption and] this which is mortal puts on immortality, then the saying will take place that is written: “Death is swallowed up forever.” 55 “Death, where is your victory? Death, where is your sting?" 1Cor15:50