Yes, I have studied the immortality of the soul and found it to be a Platonic idea, not a biblical idea.
Yes, God views sin very seriously, seriously enough to warn us of the consequences: pain and misery in this life, and finally, death. Rom. 6:23 The wages of sin is death. Death is pretty serious stuff but I'm not going to make up eternal suffering just to make it seem more serious. I'm not into make-it-up-as-you-go religion.
Yes, God is holy, absolutely holy, but there is nothing about that that demands that God punish someone forever for one single sin, especially when people don't have a snowball's chance in hell of avoiding sin. If a holy God is going to judge us so severely for sin then don't you think a merciful God would have done a better job of making us so we have at least half a chance of not sinning rather than zero chance? That's like me judging my 6 year old kids for not being as tall as I am. No just, holy, merciful, or loving God is going to punish so severely for something we have no chance to avoid. If you think he would, you have created a monstrous God in your own head. Try re-interpreting the scriptures differently so you don't make God out to be a sadistic monster, OK?
You are applying human logic to God and that is not always possible because His ways and thoughts are far above ours.
As the immortallity of the soul as taught by Plato:
Plato’s main argument for the immortality of the soul is found in his Phaedo. Following contemporary Greek religious belief and Socrates assumption that everything is involved in an eternal cyclical process, Plato naturally understands immortality (and pre-existence) of the soul in terms of reincarnation. Plato draws an analogy with sleep. Sleep comes after being awake and being awake comes after sleep. Likewise just as death comes from life so must death return to life
His doctrine is a mixture of eastern mysticism and reincarnation.
According to an ancient Greek concept of immortality (e.g. Plato), human beings ARE a soul and only HAVE a body. Death is the separation of the soul and the body. This is a form of dualism. The Christian view sees soul and body as unified in personhood. The Human being is a souled body. This becomes clear in the New Testament, which uses the term immortality exclusively in the context of the resurrection body. Human beings are not viewed as existing, at least permanently, without a body. The period of time between the physical death of a human and the resurrection of the human is the temporal period during which the human is without a body, but this is neither the original design in creation nor the ultimate end of the human.
The Old Testament contains a number of references to immortality. King David referred specifically to the resurrection of the Messiah noting that His body would not be abandoned to the grave (Psalm 16:10). This passage from Isaiah speaks for itself, “Your dead will live; their corpses will rise. You who lie in the dust, awake and shout for joy, for your dew is as the dew of the dawn, And the earth will give birth to the departed spirits.” (Isaiah 26:19). In the 8th century B.C., the prophet Elijah was taken up into heaven in the Old Testament (2 Kings 2:9-11), and then he was returned briefly to earth in the New Testament (Mark 9:2-13). These passages are quite direct in their references to immortality. Now let's consider the New Testament.
The New Testament
The New Testament is replete with references to immortality. Here's just one: The apostle Paul, who wrote approximately two-thirds of the New Testament after the gospels, wrote a lengthy discourse in the fifteenth chapter of 1 Corinthians about the bodily resurrection of both Jesus Christ and his followers. I will quote just two brief portions of it here. “But now Christ has been raised from the dead, the first fruits of those who are asleep. For since by a man came death, by a man also came the resurrection of the dead. For as in Adam all die, so also in Christ all will be made alive. But each in his own order: Christ the first fruits, after that those who are Christ’s at his coming,” (1 Corinthians 15:20-23) and “behold, I tell you a mystery; we will not all sleep, but we will all be changed, in a moment, in the twinkling of an eye, at the last trumpet; for the trumpet will sound, and the dead will be raised imperishable, and we will be changed. For this perishable must put on the imperishable, and this mortal must put on immortality. but when this perishable will have put on the imperishable, and this mortal will have put on immortality, then will come about the saying that is written, “DEATH IS SWALLOWED UP in victory. “O DEATH, WHERE IS YOUR VICTORY? O DEATH, WHERE IS YOUR STING?”” (1 Corinthians 15:51-55)
There is no question that the Bible, in both the Old and New Testaments, clearly communicates the doctrine of the immortality of the soul. This is a central truth of Christian teaching. And, according to the prophesy mentioned above from Isaiah, the doctrine applies to both Christians and non-Christians, both Jews and Gentiles, believers and unbelievers. The Bible teaches that all humans will experience life after death; some will spend eternity in heaven and the rest will spend it in hell.
God is love. God is Holy. God is just. He is The God of grace and forgiveness. God is not a sadistic monster (as you say that I and others that believe in eternal punishment have created) but He is wholly good and infinite and as such some His ways cannot be fathomed by His finite creatures.
Pete