I should clarify that I have been using the word "heaven" in the OP to mean just that.
Language that most Christians and even non-Christians relate to.
Believers leaving the physical realm to be with God in the spiritual realm.
I don't believe in unconscious nonexistence in the afterlife.
So to most people, death is not death at all.....it’s just the gateway to another kind of life? Where does the Bible say that? Can we explore what the Bible teaches...?
What was Adam told would happen to him at death?
Gen 3:19...
“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.”
Adam would go back to where he came from....back to a state of non-existence....so, why do humans fight that notion? Because they still react like Eve, believing the lie that
“you surely will not die”.....as beings programmed to live forever, it is inconceivable to imagine ourselves simply going back to the dust, which is what takes place for everyone. Death is as foreign to us now, as it ever was. It’s the reason why we fight to live. If we go to somewhere better, why do we grieve?
As Solomon wrote....
“For the living know that they will die, but the dead know nothing at all, nor do they have any more reward, because all memory of them is forgotten. . . . .Whatever your hand finds to do, do with all your might, for there is no work nor planning nor knowledge nor wisdom in the Grave, [sheol] where you are going.”
This is what Jews were taught. So I can see how plainly satan has used our natural desire to go on living, to perpetuate his first lie....it is still promoted to this day....by Christians or non-Christians alike....each with their own embellishments....but it is not a Bible teaching.
In all false religions around the world, this one belief stands as universal....
”you surely will not die”....that belief was not held by God’s people in the same way as the pagans believed it....they were taught that death is just a temporary state of ‘suspended animation’....an unconscious “sleep” from which they would awaken in “the resurrection”. There was no immortal soul that exited the body at death, to go somewhere else, but they were taught to look forward to a restoration of body and soul (the whole person) under the rule of Messiah’s Kingdom.
One Bible example explains it clearly....the resurrection of Jesus’ friend Lazarus.
John 11:11-14....
“After he said these things, he added: “Lazʹa·rus our friend has fallen asleep, but I am traveling there to awaken him.” 12 The disciples then said to him: “Lord, if he is sleeping, he will get well.” 13 Jesus, however, had spoken about his death. But they imagined he was speaking about taking rest in sleep. 14 Then Jesus said to them plainly: “Lazʹa·rus has died”.
Where was Lazarus, who had been dead for four days? Jesus said he was “asleep” and that he was going to wake him up.
In Jesus’ day, there had been no miracles since the days of the prophets hundreds of years before, so a resurrection or any other miracle, was not a common event and it elicited awe and wonder. Jesus was the first to perform such miracles in his day.
Lazarus’ sister stated her belief in “the resurrection” as the account relates...
“20 When Martha heard that Jesus was coming, she went to meet him; but Mary kept sitting at home. 21 Martha then said to Jesus: “Lord, if you had been here, my brother would not have died. 22 Yet even now I know that whatever you ask God for, God will give you.” 23 Jesus said to her: “Your brother will rise.” 24 Martha said to him: “I know he will rise in the resurrection on the last day.” 25 Jesus said to her: “I am the resurrection and the life. The one who exercises faith in me, even though he dies, will come to life; 26 and everyone who is living and exercises faith in me will never die at all. Do you believe this?”
Martha had no notion of her brother’s spirit existing in the invisible realm, because she knew about the resurrection to come “on the last day”....so when was this “last day”? Obviously she was pointing forward to the future when
“all those in their tombs would hear his [Jesus] voice and come out”. (John 5:28-29) This was under the kingdom’s rule when Jesus would call all the dead from their graves......how could he do that unless they were all still in those graves? They expected to be called back to this life on earth.
Did Lazarus mention being anywhere else when he waddled out, still in his grave wrappings?
And if he was in a better place, why would Jesus bring him back to this life, only to die again in the future?
Jewish expectation of that time, is hardly ever taken into account when we examine the subject of death, and eventually they too succumbed to the notion of an immortal soul, but it was never part of their Scripture.
When Jesus died, he remained in his tomb for three days...he did not go anywhere, but was as he stated....
”in the heart of the earth, as Jonah was in the belly of the fish”.....it was a confinement. So death is a confinement for us too, until it is time for God to bring back all the victims of Adam’s sin.
Even Christ’s elect were to sleep in death until his return.
1 Thess 4:13-17 shows us that death is not permanent except for those whom God consigns to “Gehenna” (the goats).....a place of no return....a death from which there is no resurrection.
“Gehenna” and “hades” are often translated as “hell” but they are two entirely different destinations.
Those in “hades” are released from death...those in “Gehenna” are not. (Rev 20:13-14; Matt 25:31-33, 41, 46)
So, only two groups of living things will end up in that place of no return....the “goats” (humans on earth who follow the devil’s lead) and those whom satan managed to mislead in God’s family of ‘sons’ in heaven.
They will forfeit their lives forever. No need to torture anyone.
Life or death is all God’s children were ever taught about....and either obedience, or disobedience, will dictate where each will spend eternity.