But Allah created hell in the first place, when there was no need for it.
And he created mankind when there was also no need.
He then created the conditions under which he sends people to hell.
So, how is any of that "merciful" or "just", and how is any of it anyone's responsibility but god's?
Salam
God could've not created anything and also he could've created things in a way that guarantees their guidance.
He looked at his creation and was happy that it was good, and really lucked out with the exalted best of the best.
But he took a gamble when trying Angels with Adam, it was expected all prostrate to Adam but not all did. Then took a gamble and let Iblis challenge his chosen Adam and humanity. Then when things unexpectedly fell apart, he took a further gamble in creating a fallen world.
The Torah has a verse that God regretted creating humans when Noah's people were drowned. We had in us now a culture, that would rebel against God and deny his signs.
Both Jinn and Humans, this was not odd or bad or evil or strange, it became the norm. Time and time again.
I use to find fault with that verse, but after reflecting, it seems it's true.
God wanted a perfect world. When Error handling world was created, it was to fix us and help us and guide us back, but the result is the opposite. And this is God's words in my view:
"...
and if he wished he could've gave every soul it's guidance, but his word has come true (ie. promise to Iblis) that he will fill the hell with humans and Jinn all together (that disbelieve)"
It seems it's saying God could've created this world in a way that guarantees guidance, but the gambles were made, and his promise remains, and so there is no turning back now.
This is a sad world. And God expresses his grief in Surah Yaseen:
"
Oh (intense) grief over my servants, there comes not them a Messenger except regarding him they would mock."
So why did he gamble? In my view, it's because the reward in freely choosing to worship God is just better. His relationship with us would be better. We would feel better about ourselves and each other and him.
It was unexpected that Iblis refuses. It was unexpected Adam the elite chosen one, doubts and wavers. It was unexpected humanity turns away from chosen Guides like Seth, Enoch, and Noah, and disobey God.
What has happened has happened.
There is still a way to fix things before the final non-Nabi Messenger comes, the Mahdi. And the return of Jesus and Elijah and Enoch and other chosen ones, we can prepare for them, bringing them back on good terms.
If they come back on bad terms, I fear the disgrace that will fall upon us will be great and cities destroyed will be majority (with very little believing).