Heaven is juxtaposed on Earth;
Eph 2:5 even when we were dead in trespasses, made us alive together with Christ (by grace you have been saved),
Eph 2:6 and raised us up together, and made us sit together in the heavenly places in Christ Jesus,
Hell is also juxtaposed, for it is a district of the spiritual realm;
Mat 16:18 And I also say to you that you are Peter, and on this rock I will build My church, and the gates of Hades shall not prevail against it.
So, not only is it possible for people's souls to repent while in Hell, it is a necessary condition for salvation, specifically to effect the common salvation from the polutions of the world. The polutions of the world are the result of sin. We are made clean (purged, as in purgatory) by faith and pedlution, so there is no need for a purgatory-like construct;
In John 3:16-18 “world” (2889 κόσμος kosmos) appears four times, contrasting the kosmos from whence God’s Son came with “the kosmos of humanity.” Therefore, it is impossible God sent His Son to save only some in the kosmos — excluding all born before Christ came or didn’t hear the Gospel of Christ after the 1st century. God sent His Son to save the entire kosmos (Jn. 1:9, 29; 4:42; Rm. 5:10; 8:32; 2 Cor. 5:19) whether living or dead (Jn. 5:24-25, 28-29; Heb. 9:26-28; 1 Pt. 4:6) , all born into it since the world began. (1 Jn. 2:2; 4:9-10; 8:32)16 “For God so loved the world (2889 κόσμος kosmos) that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.
17 “For God did not send His Son into the world (2889 κόσμος kosmos) to condemn the world (2889 κόσμος kosmos) , but that the world (2889 κόσμος kosmos) through Him might be saved.
18 “He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. (John 3:16-18 NKJ)
The writer of the Book of Hebrews explains how God accomplished this. His only begotten Son didn’t offer His sacrifice in the literal Temple in Jerusalem, but in heavenly Temple itself. Moreover, unlike the High Priest who offers sacrifice every year for those alive at that time, Christ appeared once at the “end of the ages” so His sacrifice would “put away sin” for all humanity born on earth since “the foundation of the kosmos“.
From God’s timeless perspective, “the Lamb” was “slain from the foundation of the world”, in other words, the moment God began to create “the lamb of God who takes away the sin of the world was slain” and names of those He saved were written in the Book of Life:24 For Christ has not entered the holy places made with hands, which are copies of the true, but into heaven itself, now to appear in the presence of God for us;
25 not that He should offer Himself often, as the high priest enters the Most Holy Place every year with blood of another–
26 He then would have had to suffer often since the foundation of the world (2889 κόσμος kosmos); but now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself. (Heb. 9:24-26 NKJ)
The next day John saw Jesus coming toward him, and said, “Behold! The Lamb of God who takes away the sin of the world (Jn. 1:29 NKJ)
[The names of those who worship the Antichrist were not written in the Book of Life from the foundation of the world:]
Confirming this interpretation is correct, the writer to the Hebrews observes all humanity in the world die once, but then they undergo a “trial,” a “judgment.” Those who pass then “eagerly wait” for Christ’s second coming when He appears apart from sacrificing Himself for sin, to save them from hell:
But what of the mockers who think it strange Christians quit their former lives of excess, and so refuse to believe the gospel? Will God give them a second chance? The Apostle Peter says “yes”, even those who mocked Christians while alive will hear the gospel preached to them, so they can repent and believe and live according to God in their spirit while still in Hell:27 And as it is appointed for men to die once, but after this the judgment,
28 so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation. (Heb. 9:27-28 NKJ)
Jesus made it clear God is very forgiving, but not for blasphemy against the Holy Spirit:3 For we have spent enough of our past lifetime in doing the will of the Gentiles– when we walked in lewdness, lusts, drunkenness, revelries, drinking parties, and abominable idolatries.
4 In regard to these, they think it strange that you do not run with them in the same flood of dissipation, speaking evil of you.
5 They will give an account to Him who is ready to judge the living and the dead.
6 For this reason the gospel was preached also to those who are dead, that they might be judged according to men in the flesh, but live according to God in the spirit. (1 Pt. 4:3-6 NKJ)
Acceptance or rejection of the Gospel of Christ are the ONLY grounds for Judgment:31 “Therefore I say to you, every sin and blasphemy will be forgiven men, but the blasphemy against the Spirit will not be forgiven men.
32 “Anyone who speaks a word against the Son of Man, it will be forgiven him; but whoever speaks against the Holy Spirit, it will not be forgiven him, either in this age or in the age to come. (Matt. 12:31-32 NKJ)
Jesus said to him, “I am the way, the truth, and the life. No one comes to the Father except through Me. (Jn. 14:6 NKJ)
11 “This is the `stone which was rejected by you builders, which has become the chief cornerstone.’
12 “Nor is there salvation in any other, for there is no other name under heaven given among men by which we must be saved.” (Acts 4:11-12 NKJ)
Therefore, God will judge everyone in the world of human existence, living or dead—only after a definite and formal presentment of the Gospel of Christ enables conscious and deliberate acceptance or rejection of Christ.17 “For God did not send His Son into the world to condemn the world, but that the world through Him might be saved.
18 “He who believes in Him is not condemned; but he who does not believe is condemned already, because he has not believed in the name of the only begotten Son of God. (Jn. 3:17-18 NKJ)
All in “the graves” who do good after hearing Christ’s voice will rise from Hell to a resurrection of life:For this reason the gospel was preached also to those who are dead, that they might be judged according to men in the flesh, but live according to God in the spirit. (1 Pt. 4:6 NKJ)
28 “Do not marvel at this; for the hour is coming in which all who are in the graves will hear His voice
29 “and come forth– those who have done good, to the resurrection of life, and those who have done evil, to the resurrection of condemnation. (Jn. 5:28-29 NKJ)