Why does Allah want to fill Hell with humans and jinn and torment them, when He is the Most Merciful, capable of guiding them, as stated in the verse: "And if We had willed, We could have given every soul its guidance, but the word from Me will come true: 'I will surely fill Hell with jinn and mankind all together'"?

The noble verse: {from jinn and humankind, all together}. The entry of the people of Paradise into Paradise and the entry of the people of Hellfire into Hellfire is the truth that befits the wisdom of each person's destiny according to their deeds, in order to uphold truth and abolish falsehood; for Allah knew that they were among the wretched. And His wisdom and justice necessitated not equating believers with transgressors.

Hell will be filled with those who deserve punishment. Allah is self-sufficient and does not need to punish His servants, nor does He desire that from them legislatively, but they wrong themselves. And the Word has been justly decreed upon most of them, due to Allah's perfect knowledge and penetrating wisdom, that He will fill Hell with jinn and humankind.

Allah's mercy and attributes are inseparable from His knowledge, wisdom, justice, and might, for His decree proceeds according to all of them. And the existence of evil in the world does not negate His mercy; rather, it is part of a broader wisdom for achieving a greater good, just as a father causing pain to his child through cupping is a sign of the completeness of his mercy. And the Qur'anic evidence confirms that if Allah were to remove distress from some people, they would persist in their transgression. Moreover, there are interpretations that the "just decree" in the verse is clear in its alignment with wisdom, for Allah did not create the heavens and the earth in play.