The Wisdom for which Allah Tests the People
7-10-2018 | IslamWeb
Question:
Assalamu Alaikum Shaikh....before starting my question I want to say that I believe in ALLAH'S wisdom and His wills behind every unexplainable and unexplained matter....Now may I know from you any possible/ guessed answer from your human wisdom that, " Why did ALLAH put us in test, when HE knows everything about the result ? " ???
Answer:
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad 
is His slave and Messenger.
First of all, we warn you about the seriousness of indulging in the hidden matters of predestination. Here, we remind you of what at-Tahawi said in his book al-‘Aqeedah at-Tahawiyyah, about this subject, as he said:
“The origin of predestination is the secret of Allah in His Creation; no close angel nor sent Prophet knows it; investigating this matter and looking deep into it is a means that leads to betrayal, an escalation to prevention, and a degree of oppression. Therefore, beware of this: you should neither investigate it nor have whispers about it.
Allah has kept the knowledge of predestination hidden from His Creation, and forbade them from asking about matters that does not concern them. Allah Says in his book (what means): {He is not questioned about what He does, but they will be questioned.} [Quran 21:23]
Secondly, Allah is the Creator of this universe; He does whatever He wishes and ordains what He intends. All this according to His Knowledge and Wisdom; which His Servants may know or may not know. In any case, a person must completely submit himself to his Lord.
Allah Says (what means): {It is not for a believing man or a believing woman, when Allah and His Messenger have decided a matter, that they should [thereafter] have any choice about their affair. And whoever disobeys Allah and His Messenger has certainly strayed into clear error.} [Quran 21:23]
Thirdly, the knowledge of Allah of what His Slaves do (or will do) is a matter pertaining to His Lordship. Allah Says (what means): {Does He who created not know, while He is the Subtle, the Acquainted?} [Quran 67:14]
How is it that Allah is the Lord of everything while He does not know their fate and outcome? A God Who does not know the future of His Creatures and does not know whether they will be obedient to Him or disobedient, and does not know who will be punished among them and who will be forgiven, does not deserve to be God because His knowledge did not encompass what he has created.
Fourthly, it is part of wisdom that Allah does not punish anyone by virtue of His Knowledge until the evidence is established against them, by the appearance of their acts. It is for this reason that He tested them, and it is in order to establish the evidence that He sent the Messengers and sent down the Books; Allah Says (what means): {[We sent] messengers as bringers of good tidings and warners so that mankind will have no argument against Allah after the messengers. And ever is Allah Exalted in Might and Wise.} [Quran 4:165]
AI-Mugheerah ibn Shu'bah 
narrated that the Prophet said: “There is none who is more fond of accepting an excuse than Allah, and for this reason, He has sent Messengers, announcers of glad tidings and warners.” [Al-Bukhari and Muslim]
Fifthly, the Muslim is created to be tested and entrusted to perform Islamic obligations; so he should obey the command of Allah Almighty, and ask Him to grant him success to do all that is good. ‘Ali narrated that the Prophet said:
“There is none among you but has his place written for him, either in Paradise or in Hellfire." They (the Companions) said: “O Messenger of Allah! Shall we depend upon what has been written for us (and give up doing good deeds)?'' He (the Prophet) replied, "No! Carry on doing good deeds, for everybody will find easy (to do) such deeds (as will lead him to his destined place) for which he has been created.” [Al-Bukhari and Muslim]
Sixthly, the fact that Allah rewards His Slaves for their deeds is an appearance of the effects of the Names and Attributes of Allah: He is the Creator, the Sustainer, the Giver of life, the One who causes death, the Most Merciful, the Most Compassionate, the Wise and the All-Knower. He gives victory to the believers and disgraces the disbelievers, and it is He who holds his servants accountable and rewards them for their actions... etc.
Allah knows best.