In the name of God, the Most Merciful, Most Beneficent
"...He whom Allah guides is the [rightly] guided, but he whom He sends astray - never will you find for him a protecting guide." (18:17) - among a few other verses on this subject.
This is among some tough questions in Islam. There is not a straight forward answer and it takes many aspects of our iman to take this in.
God has answered this question in the Quran. As Sajdah (32:13) transliterated: "And if We had willed, We could have given every soul its guidance, but the word from Me will come into effect [that] "I will surely fill Hell with jinn and people all together."
This is a very big test in gauging our humility, as a servant of God who has no power over God's will. This puts us in our place. Only our understanding of God's power and our true humility as a servant of God can make us accept this wholeheartedly - that we accept the fact that we ARE truly at His Mercy. It is God who has ultimate power over all of us and all of the universe. We have no power but to SURRENDER OURSELVES to God - which is what it means to be a true Muslim. Allaahu Akbar.
As Muslims, we understand that God knows best, and we know next to nothing - we, as in we human, including the most knowledgeable of scientists. We know only what God allows us to know. (2:32 : "They [the Angels] said, "Exalted are You; we have no knowledge except what You have taught us. Indeed, it is You who is the Knowing,1 the Wise.")
We cannot be so arrogant as to demand to know the meaning behind every of God's actions and Words, as if we can understand everything fully. We cannot encompass and understand the much greater part of God's plans and God's knowledge. We accept that God knows and we know not.
But then again, as a Muslim, the other aspect of our iman, tells us to put our full trust in God " for Allah loves those who put their trust in Him." (3:159). God has promised, and His promise is true, that if we have faith in the One God, we don't assign partners to Him in our worship, we believe in the akhirah and we do good, then, we have nothing to fear. Put our trust in him and just focus on our iman and good deeds.
God is Most Merciful, as God most frequently and repeatedly state in the Quran, He is Ar-Rahman. His Mercy will reign in Akhirah. "Abu Huraira reported that Allah's Messenger (ﷺ) said: When Allah created the creation as He was upon the Throne, He put down in His Book: Verily, My mercy predominates My wrath." Sahih Muslim
So the answer is to surrender fully, put your trust in Allaah and Allaah will be as how His servants deem Him to be.
Narrated Abu Huraira:
The Prophet (ﷺ) said, "Allah says: 'I am just as My slave thinks I am, (i.e. I am able to do for him what he thinks I can do for him) and I am with him if He remembers Me. If he remembers Me in himself, I too, remember him in Myself; and if he remembers Me in a group of people, I remember him in a group that is better than they; and if he comes one span nearer to Me, I go one cubit nearer to him; and if he comes one cubit nearer to Me, I go a distance of two outstretched arms nearer to him; and if he comes to Me walking, I go to him running.' " Sahih Bukhari
May Allaah grant us humility as His servants, grant us wisdom and understanding, a good iman and a good result in the world and the Hereafter. Aamiin.
