Allah tells us about the rebellion of the disbelievers in ancient times and in more recent times, and how they rejected the obvious truth even when they witnessed clear signs and proofs. Nothing stopped them from following the truth except their demand to witness with their own eyes the punishment which they were being warned about. As some of them said to their Prophet:

فَأَسْقِطْ عَلَيْنَا كِسَفاً مِّنَ السَّمَآءِ إِن كُنتَ مِنَ الصَّـدِقِينَ

(So cause a piece of the heaven to fall on us, if you are of the truthful!) 26:187, Others said:

ائْتِنَا بِعَذَابِ اللَّهِ إِن كُنتَ مِنَ الصَّـدِقِينَ

(Bring Allah's torment upon us if you are one of the truthful.) 29:29 The Quraysh said:

اللَّهُمَّ إِن كَانَ هَـذَا هُوَ الْحَقَّ مِنْ عِندِكَ فَأَمْطِرْ عَلَيْنَا حِجَارَةً مِّنَ السَّمَآءِ أَوِ ائْتِنَا بِعَذَابٍ أَلِيمٍ

(O Allah! If this is indeed the truth from You, then rain down stones on us from the sky or bring upon us a painful torment.) 8:32

وَقَالُواْ يأَيُّهَا الَّذِى نُزِّلَ عَلَيْهِ الذِّكْرُ إِنَّكَ لَمَجْنُونٌ - لَّوْ مَا تَأْتِينَا بِالْمَلَـئِكَةِ إِن كُنتَ مِنَ الصَّـدِقِينَ

(And they say: "O you to whom the Reminder has been sent down! Verily, you are a mad man! Why do you not bring angels to us if you are of the truthful") 15:6-7. There are other Ayat refering to the same thing. Then Allah says:

إِلاَّ أَن تَأْتِيَهُمْ سُنَّةُ الاٌّوَّلِينَ

(except that the ways of the ancients be repeated with them,) meaning, their overwhelming punishment, destroying every last one of them.

أَوْ يَأْتِيَهُمُ الْعَذَابُ قُبُلاً

(or the torment be brought to them face to face.) they see it with their own eyes, being directly confronted with it. Then Allah says:

وَمَا نُرْسِلُ الْمُرْسَلِينَ إِلاَّ مُبَشِّرِينَ وَمُنذِرِينَ

(And We send not the Messengers except as bearers of good news and warners.) before the punishment they give good news to those who believe in them and follow them, and warnings to those who reject them and oppose them. Then Allah tells us about the disbelievers who argue:

بِالْبَـطِلِ لِيُدْحِضُواْ بِهِ الْحَقَّ

(with falsehood, in order to refute the truth thereby.) they try to weaken the truth that the Messengers brought, but they cannot achieve that.

وَاتَّخَذُواْ ءايَاتِى وَمَا أُنْذِرُواْ هُزُواً

(And they take My Ayat and that which they are warned for jest!) they take the proof, evidence and miracles sent with the Messengers to warn them, and make them fear the punishment;

هُزُواً

(as a jest and mockery) and they make fun of them, which is the worst type of disbelief.

وَمَنْ أَظْلَمُ مِمَّن ذُكِّرَ بِـَايِـتِ رَبِّهِ فَأَعْرَضَ عَنْهَا وَنَسِىَ مَا قَدَّمَتْ يَدَاهُ إِنَّا جَعَلْنَا عَلَى قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِى ءَاذَانِهِمْ وَقْراً وَإِن تَدْعُهُمْ إِلَى الْهُدَى فَلَنْ يَهْتَدُواْ إِذاً أَبَداً - وَرَبُّكَ الْغَفُورُ ذُو الرَّحْمَةِ لَوْ يُؤَاخِذُهُم بِمَا كَسَبُواْ لَعَجَّلَ لَهُمُ الْعَذَابَ بَل لَّهُم مَّوْعِدٌ لَّن يَجِدُواْ مِن دُونِهِ مَوْئِلاً