God asks in the Quran questions to people that he is not waiting for an answer from them. The question itself has the right answer. It is a way of providing information in the form of question. It is a great way of teaching people. It invokes your intellect and the deep understanding of the message in the question. It also testyify to the power of the speaker and he is God. He does not want our answers but our understanding. I give here few examples.
1- Is not God who has the creation and commandment?: God is the creator of the earth and heavens, day, night, the sun, the moon and the stars. The one who created is the one who to have the commandment.
7:54 Lo! your Lord is Allah Who created the heavens and the earth in six Days, then mounted He the Throne. He covereth the night with the day, which is in haste to follow it, and hath made the sun and the moon and the stars subservient by His command. His verily is all creation and commandment Blessed be Allah, the Lord of the Worlds! إِنَّ رَبَّكُمُ اللّهُ الَّذِي خَلَقَ السَّمَاوَاتِ وَالأَرْضَ فِي سِتَّةِ أَيَّامٍ ثُمَّ اسْتَوَى عَلَى الْعَرْشِ يُغْشِي اللَّيْلَ النَّهَارَ يَطْلُبُهُ حَثِيثًا وَالشَّمْسَ وَالْقَمَرَ وَالنُّجُومَ مُسَخَّرَاتٍ بِأَمْرِهِ أَلاَ لَهُ الْخَلْقُ وَالأَمْرُ تَبَارَكَ اللّهُ رَبُّ الْعَالَمِينَ (7:54)
2- God asks the disbelievers about their creation: are they created from non-existence or they are the creators? (since we are the only intelligent creation we know of).
52:35 Have they themselves been created without anything [that might have caused their creation]? Or are they the creators?أَمْ خُلِقُوا مِنْ غَيْرِ شَيْءٍ أَمْ هُمُ الْخَالِقُونَ (52:35)
3- God asks people about his signs of creation and if any of them they can deny:
-40:81 And He showeth you His tokens. Which, then, of the tokens of Allah do ye denyوَيُرِيكُمْ آيَاتِهِ فَأَيَّ آيَاتِ اللَّهِ تُنكِرُونَ (40:81)
4- God asks us: Is not by the remembrance of God hearts find rest?: the proof is in the verse the believers feel that.
13:28 Who have believed and whose hearts have rest in the remembrance of Allah. Verily in the remembrance of Allah do hearts find rest! الَّذِينَ آمَنُواْ وَتَطْمَئِنُّ قُلُوبُهُم بِذِكْرِ اللّهِ أَلاَ بِذِكْرِ اللّهِ تَطْمَئِنُّ الْقُلُوبُ (13:28)
5- God asks the disbelievers if they can prove any of the false Gods able to create?:
10:34 Say : Is there of your partners (whom ye ascribe unto Allah) one that produceth Creation and then reproduceth it? Say: Allah produceth creation, then reproduceth it. how then, are ye misled! قُلْ هَلْ مِن شُرَكَآئِكُم مَّن يَبْدَأُ الْخَلْقَ ثُمَّ يُعِيدُهُ قُلِ اللّهُ يَبْدَأُ الْخَلْقَ ثُمَّ يُعِيدُهُ فَأَنَّى تُؤْفَكُونَ (10:34)
6- God asks the disbeliever: Where are they turnning to?: God is the truth and beyond him is error so where are you turning to.
10:32 Such then is Allah, your rightful Lord. After the Truth what is there saving error? how then are ye turned away! فَذَلِكُمُ اللّهُ رَبُّكُمُ الْحَقُّ فَمَاذَا بَعْدَ الْحَقِّ إِلاَّ الضَّلاَلُ فَأَنَّى تُصْرَفُونَ (10:32)
7- God asks us the disbelievers why do they disbelieve?: and they were not and now they are and they will die and return to him:
2:28 How disbelieve ye in Allah when ye were dead and He gave life to you! Then he will give you death, then life again, and then unto Him ye will return. كَيْفَ تَكْفُرُونَ بِاللَّهِ وَكُنتُمْ أَمْوَاتاً فَأَحْيَاكُمْ ثُمَّ يُمِيتُكُمْ ثُمَّ يُحْيِيكُمْ ثُمَّ إِلَيْهِ تُرْجَعُونَ (2:28)
وَكَيْفَ تَكْفُرُونَ وَأَنتُمْ تُتْلَى عَلَيْكُمْ آيَاتُ اللّهِ وَفِيكُمْ رَسُولُهُ وَمَن يَعْتَصِم بِاللّهِ فَقَدْ هُدِيَ إِلَى صِرَاطٍ مُّسْتَقِيمٍ (3:101) 3:101 (Picktall) how can ye disbelieve, when Allah's revelations are recited unto you, and His messenger is in your midst? He who holdeth fast to Allah, he indeed is guided unto a right path. -
8- God asks the people of the book why they disbelieve in Islam: while they bear witness it is the turth since its prophet was described to them and the Quran describes to them the truth of their religions.
3:70 O People of the Scripture! why disbelieve ye in the revelations of Allah, when ye (yourselves) bear witness (to the truth) ? يَا أَهْلَ الْكِتَابِ لِمَ تَكْفُرُونَ بِآيَاتِ اللّهِ وَأَنتُمْ تَشْهَدُونَ (3:70)
3:71 O People of the Scripture! why confound ye truth with falsehood and knowingly conceal the truth? يَا أَهْلَ الْكِتَابِ لِمَ تَلْبِسُونَ الْحَقَّ بِالْبَاطِلِ وَتَكْتُمُونَ الْحَقَّ وَأَنتُمْ تَعْلَمُونَ (3:71)
3:98 Say: O People of the Scripture! why disbelieve ye in the revelations of Allah, when Allah (Himself) is Witness of what ye do. قُلْ يَا أَهْلَ الْكِتَابِ لِمَ تَكْفُرُونَ بِآيَاتِ اللّهِ وَاللّهُ شَهِيدٌ عَلَى مَا تَعْمَلُونَ (3:98)
3:99 Say: O People of the Scripture! why drive ye back believers from the way of Allah, seeking to make it crooked, when ye are witnesses (to Allah's guidance)? Allah is not unaware of what ye do. قُلْ يَا أَهْلَ الْكِتَابِ لِمَ تَصُدُّونَ عَن سَبِيلِ اللّهِ مَنْ آمَنَ تَبْغُونَهَا عِوَجًا وَأَنتُمْ شُهَدَاء وَمَا اللّهُ بِغَافِلٍ عَمَّا تَعْمَلُونَ (3:99)
9- God asks the disbelievers why they strive to reach the fire: why they sell guidance for error.2:175 Those are they who purchase error at the price of guidance, and torment at the price of pardon. how constant are they in their strife to reach the Fire! أُولَـئِكَ الَّذِينَ اشْتَرَوُاْ الضَّلاَلَةَ بِالْهُدَى وَالْعَذَابَ بِالْمَغْفِرَةِ فَمَآ أَصْبَرَهُمْ عَلَى النَّارِ (2:175)
10- God asks Muhammad about those disbelievers of the past if he sees or hear one of them: Which gives you the power of God in their destruction and in being eternal and the disblievers just comes and goes.
19:98 And how many a generation before them have We destroyed! Canst thou (Muhammad) see a single man of them, or hear from them the slightest sound? وَكَمْ أَهْلَكْنَا قَبْلَهُم مِّن قَرْنٍ هَلْ تُحِسُّ مِنْهُم مِّنْ أَحَدٍ أَوْ تَسْمَعُ لَهُمْ رِكْزًا (19:98)
11- How then it will be when it will be (the day of judgament):
فَكَيْفَ إِذَا جَمَعْنَاهُمْ لِيَوْمٍ لاَّ رَيْبَ فِيهِ وَوُفِّيَتْ كُلُّ نَفْسٍ مَّا كَسَبَتْ وَهُمْ لاَ يُظْلَمُونَ (3:25)
3:25 (Picktall) How (will it be with them) when We have brought them all together to a Day of which there is no doubt, when every soul will be paid in full what it hath earned, and they will not be wronged.
12-God asks man how remembrance will help him in the day of judgment: the answer is easy it will be too late when he sees hell, face to hell.
89:23 And hell is brought near that day; on that day man will remember, but how will the remembrance (then avail him)? وَجِيءَ يَوْمَئِذٍ بِجَهَنَّمَ يَوْمَئِذٍ يَتَذَكَّرُ الْإِنسَانُ وَأَنَّى لَهُ الذِّكْرَى (89:23)