SalamHmm, okay. Sounds like a pretty vengeful God to me, though.
Another component, is that a soul becomes irreformable per my paradigm in the long run. So he created heaven and hell with life and death pressure time, to quickly save us from that path. So he is quick to reckon and tries us by harms as well, but both hands of his mercy and wrath, are for mercy at the end. Hell and threats are an attempt to save our souls from spiraling down with no way to save it. To better explain:
First principle, endless lives or a second chance won't reform a soul
I will do good, mere word
لَعَلِّي أَعْمَلُ صَالِحًا فِيمَا تَرَكْتُ ۚ كَلَّا ۚ إِنَّهَا كَلِمَةٌ هُوَ قَائِلُهَا ۖ وَمِنْ وَرَائِهِمْ بَرْزَخٌ إِلَىٰ يَوْمِ يُبْعَثُونَ | that I may act righteously in what I have left behind.’ ‘By no means! These are mere words that he says.’ And before them is a barrier until the day they will be resurrected. | Al-Muminoon : 100
They are liars now and won't be able to fulfill their pledge
وَلَوْ تَرَىٰ إِذْ وُقِفُوا عَلَى النَّارِ فَقَالُوا يَا لَيْتَنَا نُرَدُّ وَلَا نُكَذِّبَ بِآيَاتِ رَبِّنَا وَنَكُونَ مِنَ الْمُؤْمِنِينَ | Were you to see when they are brought to a halt by the Fire, whereupon they will say, ‘If only we were sent back [into the world]! Then we will not deny the signs of our Lord, and we will be among the faithful!’ | Al-An'aam : 27
بَلْ بَدَا لَهُمْ مَا كَانُوا يُخْفُونَ مِنْ قَبْلُ ۖ وَلَوْ رُدُّوا لَعَادُوا لِمَا نُهُوا عَنْهُ وَإِنَّهُمْ لَكَاذِبُونَ | Indeed, what they used to hide before has now become evident to them. But were they to be sent back they would revert to what they were forbidden, and they are indeed liars. | Al-An'aam : 28
Broke promise once, will break promise again
وَأَنْذِرِ النَّاسَ يَوْمَ يَأْتِيهِمُ الْعَذَابُ فَيَقُولُ الَّذِينَ ظَلَمُوا رَبَّنَا أَخِّرْنَا إِلَىٰ أَجَلٍ قَرِيبٍ نُجِبْ دَعْوَتَكَ وَنَتَّبِعِ الرُّسُلَ ۗ أَوَلَمْ تَكُونُوا أَقْسَمْتُمْ مِنْ قَبْلُ مَا لَكُمْ مِنْ زَوَالٍ | Warn the people of the day when the punishment will overtake them, whereat the wrongdoers will say, ‘Our Lord! Respite us for a short time so that we may respond to Your call and follow the apostles.’ [They will be told,] ‘Did you not swear earlier? There is no possibility of reverse for you, | Ibrahim : 44
There is more about the paradigm of hell in the Quran here: The Quran's framework for hell. | Religious Forums