In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

Imaam Ibnul Qayyim [may Allaah have mercy upon him] said: Whoever ponders upon the state of affairs of the world will find that every affair of rectification is due to Tawheed, singling out Allaah in worship and obedience to His Messenger (Muhammad). And every evil in the world, trial, affliction, scarcity (in livelihood), being overpowered by an enemy and other than that is due to (our) opposition to the Messenger and the call to other than (the way of) Allaah and His Messenger. Whoever truly ponders upon this and examines the state of affairs of the world- since its beginning and until the time Allaah will take it away and those upon it- he will realise this affair regarding himself and others, in general and specific (circumstances). And there is no Might or Power except with Allaah –The Most High, The Most Great. [Source: Badaa’i Al-Fawaa’id 3/525-526]

The Reasons Behind Fujoor [Wicked or Extremely Sinful Behaviour]

Misguidance necessitates extreme wicked behaviour, pride and lying, and this has been mentioned a lot in the Qur’aan. Allaah [The Exalted]:

يُضِلُّ بِهِۦ ڪَثِيرً۬ا وَيَهۡدِى بِهِۦ كَثِيرً۬ا‌ۚ وَمَا يُضِلُّ بِهِۦۤ إِلَّا ٱلۡفَـٰسِقِينَ

ٱلَّذِينَ يَنقُضُونَ عَهۡدَ ٱللَّهِ مِنۢ بَعۡدِ مِيثَـٰقِهِۦ وَيَقۡطَعُونَ مَآ أَمَرَ ٱللَّهُ بِهِۦۤ أَن يُوصَلَ وَيُفۡسِدُونَ فِى ٱلۡأَرۡضِ‌ۚ أُوْلَـٰٓٮِٕكَ هُمُ ٱلۡخَـٰسِرُونَ

Verily, Allah is not ashamed to set forth a parable even of a mosquito or so much more when it is bigger (or less when it is smaller) than it. And as for those who believe, they know that it is the Truth from their Lord, but as for those who disbelieve, they say: “What did Allah intend by this parable?” By it He misleads many, and many He guides thereby. And He misleads thereby only those who are Al-Fasiqun (the rebellious, disobedient to Allah). Those who break Allah’s Covenant after ratifying it, and sever what Allah has ordered to be joined (as regards Allah’s Religion of Islamic Monotheism, and to practise its legal laws on the earth and also as regards keeping good relations with kith and kin ), and do mischief on earth, it is they who are the losers. [Surah Al-Baqarah. Aayaat 26-27]

And Allaah [The Exalted] said:

يُثَبِّتُ ٱللَّهُ ٱلَّذِينَ ءَامَنُواْ بِٱلۡقَوۡلِ ٱلثَّابِتِ فِى ٱلۡحَيَوٰةِ ٱلدُّنۡيَا وَفِى ٱلۡأَخِرَةِ‌ۖ وَيُضِلُّ ٱللَّهُ ٱلظَّـٰلِمِينَ‌ۚ وَيَفۡعَلُ ٱللَّهُ مَا يَشَآءُ

Allah will keep firm those who believe, with the word that stands firm in this world (i.e. they will keep on worshipping Allah Alone and none else), and in the Hereafter. And Allah will cause to go astray those who are Zaalimoon (polytheists and wrong-doers, etc.), and Allah does what He wills. [Surah Ibraaheem. Aayah 27]

And Allaah [The Exalted] said: [فَمَا لَكُمۡ فِى ٱلۡمُنَـٰفِقِينَ فِئَتَيۡنِ وَٱللَّهُ أَرۡكَسَہُم بِمَا كَسَبُوٓاْ‌ۚ – Then what is the matter with you that you are divided into two parties about the hypocrites? Allah has cast them back (to disbelief) because of what they have earned. Do you want to guide him whom Allah has made to go astray? And he whom Allah has made to go astray, you will never find for him any way (of guidance)]. [Surah An-Nisaa. Aayah 88]

And Allaah [The Exalted] said: [وَقَالُواْ قُلُوبُنَا غُلۡفُۢ‌ۚ بَل لَّعَنَہُمُ ٱللَّهُ بِكُفۡرِهِمۡ فَقَلِيلاً۬ مَّا يُؤۡمِنُونَ – And they say, “Our hearts are wrapped (i.e. do not hear or understand Allah’s Word).” Nay, Allah has cursed them for their disbelief, so little is that which they believe]. [Surah Al-Baqarah. Aayah 88]

And Allaah [The Exalted] said: [وَنُقَلِّبُ أَفۡـِٔدَتَہُمۡ وَأَبۡصَـٰرَهُمۡ كَمَا لَمۡ يُؤۡمِنُواْ بِهِۦۤ أَوَّلَ مَرَّةٍ۬ – And We shall turn their hearts and their eyes away (from guidance), as they refused to believe therein for the first time]. [Surah Al-An-aam. Aayah 110]

Allaah informed us that He punished them due to their [deliberate] failure to accept Eemaan when it came to them and they recognised it, [but they] turned away from it; so, Allaah turned their hearts and eyes away and prevented them from it, just as Allaah [The Exalted] said:

يَـٰٓأَيُّہَا ٱلَّذِينَ ءَامَنُواْ ٱسۡتَجِيبُواْ لِلَّهِ وَلِلرَّسُولِ إِذَا دَعَاكُمۡ لِمَا يُحۡيِيڪُمۡ‌ۖ وَٱعۡلَمُوٓاْ أَنَّ ٱللَّهَ يَحُولُ بَيۡنَ ٱلۡمَرۡءِ وَقَلۡبِهِۦ وَأَنَّهُ ۥۤ إِلَيۡهِ تُحۡشَرُونَ

O you who believe! Answer Allah (by obeying Him) and (His) Messenger when he (Muhammad) calls you to that which will give you life, and know that Allah comes in between a person and his heart (i.e. He prevents an evil person to decide anything). And verily to Him you shall (all) be gathered. [Surah Al-Anfaal. Aayah 24]

Allaah commanded them to respond to Him and His Messenger when they are called to that which will give them life [i.e. Eemaan by way of which the hearts are guided to the right path and righteous deeds in all affairs of life], then he warned them against turning away and being delayed from responding [to His call and that of His Messenger], as a result of which their hearts would be prevented from accepting Eemaan. Allaah said [The Exalted] said: [فَلَمَّا زَاغُوٓاْ أَزَاغَ ٱللَّهُ قُلُوبَهُمۡ‌ۚ وَٱللَّهُ لَا يَہۡدِى ٱلۡقَوۡمَ ٱلۡفَـٰسِقِينَ – So when they turned away (from the Path of Allah), Allah turned their hearts away (from the Right Path). And Allah guides not the people who are Fasiqun (rebellious, disobedient to Allah)]. [Surah As-Saff. Aayah 5]

Allaah said: [The Exalted] said: [كَلَّا‌ۖ بَلۡۜ رَانَ عَلَىٰ قُلُوبِہِم مَّا كَانُواْ يَكۡسِبُونَ – Nay! But on their hearts is the Ran (covering of sins and evil deeds) which they used to earn. [Surah Al-Mutaffifeen. Aayah 14]

Allaah informed us that the evil they earned sealed their hearts and became a barrier between them and belief in Allaah’s Aayaat, as Allaah stated that they said: [أَسَـٰطِيرُ ٱلۡأَوَّلِينَ – Tales of the ancients! (i.e. the Aayaat of Allaah conveyed by the Messengers are nothing but tales of the ancients)].

And Allaah [The Exalted] said about the hypocrites: [نَسُواْ ٱللَّهَ فَنَسِيَہُمۡ‌ۗ – They have forgotten Allaah, so He has forgotten them. (i.e. prevented them from His guidance and mercy)]. [Surah At-tawbah. Aayah 67]

Allaah recompensed them for forgetting Him, so He did not mention them with guidance and mercy. Allaah [also] informed us that He made them forget themselves, so that they did not seek to perfect their souls through beneficial knowledge and righteous deeds- which is guidance and the religion of truth; made them forgetful of seeking after [guidance and the religion of truth], love of Him, knowledge and awareness of Him and being eager for it, as a punishment upon them for forgetting Him. He [The Exalted] said regarding them:

أُوْلَـٰٓٮِٕكَ ٱلَّذِينَ طَبَعَ ٱللَّهُ عَلَىٰ قُلُوبِہِمۡ وَٱتَّبَعُوٓاْ أَهۡوَآءَهُمۡ
وَٱلَّذِينَ ٱهۡتَدَوۡاْ زَادَهُمۡ هُدً۬ى وَءَاتَٮٰهُمۡ تَقۡوَٮٰهُمۡ

Such are men whose hearts Allah has sealed, and they follow their lusts (evil desires). While as for those who accept guidance, He increases their guidance, and bestows on them their piety. [Surah Muhammad. Aayaat 16-17]

They were recompensed with a combination of Ittibaa Al-Hawaa [following desires] and Dalaal [misguidance] – the [evil] fruits of following desires and its inevitable outcome, just as the people of guidance are [recompensed] with a combination of Taqwaa [Fear of Allaah] and Hudaa [upright guidance]. [Source: Al-Fawaa-id’ page 197-198. Slightly Paraphrased]