Praise be to Allah.

Firstly: 

One of the greatest attributes of Allaah is wisdom, and one of His greatest names is al-Hakeem (the most Wise). It should be noted that He has not created anything in vain; exalted be Allaah far above such a thing. Rather He creates things for great and wise reasons, and for sublime purposes. Those who know them know them and those who do not know them do not know them. Allaah has stated that in His Holy Book, where He says that He has not created mankind in vain, and He has not created the heavens and the earth in vain. Allaah says (interpretation of the meaning): 

“Did you think that We had created you in play (without any purpose), and that you would not be brought back to Us?”

So Exalted be Allaah, the True King: Laa ilaaha illa Huwa (none has the right to be worshipped but He), the Lord of the Supreme Throne!”

[al-Mu’minoon 23:115, 116] 

“We created not the heavens and the earth and all that is between them for a (mere) play”

[al-Anbiya’ 21:16] 

“And We created not the heavens and the earth, and all that is between them, for mere play.

We created them not except with truth (i.e. to examine and test those who are obedient and those who are disobedient and then reward the obedient ones and punish the disobedient ones), but most of them know not”

[al-Dukhaan 44:38] 

“HaaMeem.

[These letters are one of the miracles of the Qur’aan, and none but Allaah (Alone) knows their meanings.]

The revelation of the Book (this Qur’aan) is from Allaah, the AllMighty, the AllWise.

We created not the heavens and the earth and all that is between them except with truth, and for an appointed term. But those who disbelieve, turn away from that whereof they are warned”

[al-Ahqaaf 46:1-3] 

Just as it is proven that there is wisdom behind the creation of man from the standpoint of sharee’ah (Islamic law), it is also proven from the standpoint of reason. The wise man cannot but accept that things have been created for a reason, and the wise man regards himself as being above doing things in his own life for no reason, so how about Allaah, the Wisest of the wise? 

Hence the wise believers affirm that there is wisdom in Allaah’s creation, and the disbelievers deny that. Allaah says (interpretation of the meaning): 

“Verily, in the creation of the heavens and the earth, and in the alternation of night and day, there are indeed signs for men of understanding.

Those who remember Allaah (always, and in prayers) standing, sitting, and lying down on their sides, and think deeply about the creation of the heavens and the earth, (saying): Our Lord! You have not created (all) this without purpose, glory to You! (Exalted are You above all that they associate with You as partners). Give us salvation from the torment of the Fire”
[Aal ‘Imraan 3:190, 191] 

And Allaah says, describing the attitude of the disbelievers towards the wisdom of His creation (interpretation of the meaning): 

“And We created not the heaven and the earth and all that is between them without purpose! That is the consideration of those who disbelieve! Then woe to those who disbelieve (in Islamic Monotheism) from the Fire!”

[Saad 38:27] 

Shaykh ‘Abd al-Rahmaan al-Sa’di (may Allaah have mercy on him) said: 

Allaah tells us of His perfect wisdom in creating the heavens and the earth, and that He has not created them in vain, i.e., in play with no beneficial purpose. 

“That is the consideration of those who disbelieve” in their Lord, because they think that which does not befit His Majesty. 

“Then woe to those who disbelieve (in Islamic Monotheism) from the Fire!” Allaah created the heavens and earth in truth for truth. He created them so that His slaves might understand the completeness of His Knowledge and Power and the extent of His Might, and that He Alone is the One to be worshipped, and not those who have not created even an atom in the heavens or on earth. And that they might know that the Resurrection is true and that Allaah will judge between the people of good and evil. The one who is ignorant of the wisdom of Allaah should not think that Allaah will treat them equally when judging them. Hence Allaah says (interpretation of the meaning): 

“Shall We treat those who believe (in the Oneness of Allaah Islamic Monotheism) and do righteous good deeds as Mufsidoon (those who associate partners in worship with Allaah and commit crimes) on earth? Or shall We treat the Muttaqoon (the pious) as the Fujjaar (criminals, disbelievers, the wicked)?”

[Saad 38:28] 

This does not befit Our wisdom and Our judgement. End quote. 

Tafseer al-Sa’di, p. 712 

Secondly: 

Allaah has not created man to eat, drink and multiply, in which case he would be like the animals. Allaah has honoured man and favoured him far above many of those whom He has created, but many people insist on disbelief, so they are ignorant of or deny the true wisdom behind their creation, and all they care about is enjoying the pleasures of this world. The life of such people is like that of animals, and indeed they are even more astray. Allaah says (interpretation of the meaning): 

“while those who disbelieve enjoy themselves and eat as cattle eat; and the Fire will be their abode”

[Muhammad 47:12]

 “Leave them to eat and enjoy, and let them be preoccupied with (false) hope. They will come to know!”

[al-Hijr 15:3] 

“And surely, We have created many of the jinn and mankind for Hell. They have hearts wherewith they understand not, and they have eyes wherewith they see not, and they have ears wherewith they hear not (the truth). They are like cattle, nay even more astray; those! They are the heedless ones”

[al-A’raaf 7:179] 

It is well known to wise people that the one who does a thing knows more about the wisdom behind it than anyone else and for Allaah is the highest description (cf. al-Nahl 16:60); He is the One Who has created mankind and He knows best the wisdom behind the creation of mankind. No one would dispute this with regard to worldly matters. All people are certain that their physical faculties have been created for a reason. The eye is for seeing, the ear is for hearing, and so on. Does it make sense for his physical faculties to have been created for a reason but for himself to have been created in vain? Or does he not agree to respond to the One Who created him when He tells him of the reason behind his creation? 

Allaah has told us that the creation of the heavens and the earth, and of life and death, is for the purpose of testing, so as to test man. Whoever obeys Him, He will reward him, and whoever disobeys Him, He will punish him. Allaah says (interpretation of the meaning): 

“And He it is Who has created the heavens and the earth in six Days and His Throne was on the water, that He might try you, which of you is the best in deeds. But if you were to say to them: “You shall indeed be raised up after death,” those who disbelieve would be sure to say, “This is nothing but obvious magic”

[Hood 11:7] 

“Who has created death and life that He may test you which of you is best in deed. And He is the AllMighty, the OftForgiving”

[al-Mulk 67:2] 

From this test results a manifestation of the names and attributes of Allaah, such as Allaah’s names al-Rahmaan (the Most Gracious), al-Ghafoor (the Oft Forgiving), al-Hakeem (the Most Wise), al-Tawwaab (the Accepter of Repentance), al-Raheem (the Most Merciful), and other names of Allaah. 

One of the greatest reasons for which Allaah has created mankind – which is one of the greatest tests – is the command to affirm His Oneness (Tawheed) and to worship Him alone with no partner or associate. Allaah has stated this reason for the creation of mankind, as He says (interpretation of the meaning): 

“And I (Allaah) created not the jinn and mankind except that they should worship Me (Alone)”

[al-Dhaariyaat 51:56] 

Ibn Katheer (may Allaah have mercy on him) said: 

i.e., I have created them so that I may command them to worship Me, not because I have any need of them. ‘Ali ibn Abi Talhah said, narrating from Ibn ‘Abbaas: “except that they should worship Me (alone)” willingly or unwillingly. This is the view favoured by Ibn Jareer. Ibn Jurayj said: i.e., except that they should know Me. Al-Rabee’ ibn Anas said: “Except that they should worship Me”, i.e., for the purpose of worship. End quote. 

Tafseer Ibn Katheer, 4/239 

Shaykh ‘Abd al-Rahmaan al-Sa’di (may Allaah have mercy on him) said: 

Allaah, may He be exalted, created mankind to worship Him and to know Him by His names and attributes, and to enjoin that upon them. Whoever submits to Him and does what is enjoined upon him will be one of those who are successful, but whoever turns away from that, they are the losers. He will inevitably gather them together in the Hereafter where He will reward or punish them for what He commanded and forbade them to do. Hence Allaah mentions how the mushrikeen (polytheists) denied the reward or punishment, as He says (interpretation of the meaning): 

“But if you were to say to them: ‘You shall indeed be raised up after death,’ those who disbelieve would be sure to say, ‘This is nothing but obvious magic’”

[Hood 11:7] 

i.e., if you were to speak to these people and tell them about the Resurrection after death, they would not believe you, rather they would reject your words vehemently and deny the message you brought, and they would say, ‘This is nothing but obvious magic,’ but in fact it is obvious truth. End quote. 

Tafseer al-Sa’di, p. 333 

And Allaah knows best