Surat Al Kahf (57-58)

{وَمَنْ أَظْلَمُ مِمَّن ذُكِّرَ بِآيَاتِ رَبِّهِ فَأَعْرَضَ عَنْهَا وَنَسِيَ مَا قَدَّمَتْ يَدَاهُ إِنَّا جَعَلْنَا عَلَى قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِي آذَانِهِمْ وَقْراً وَإِن تَدْعُهُمْ إِلَى الْهُدَى فَلَن يَهْتَدُوا إِذاً أَبَداً} (الكهف: 57)

57- There is no one more oppressive than a person who is reminded of Allah's Signs, including the Qur'an, but turn away and do not ponder over them, and forget the sins and acts of disbelief which he committed.

We have placed coverings over their hearts so as not to understand Dhikr and blocked their ears so as not to hear it, for they have mocked at Allah's Signs. Indeed, Allah knew for sure that they will not believe, so he destined for them aberration, so when you call them to the true religion, they will never believe. And Allah shall not guided them as long as their hearts are sealed.

{وَرَبُّكَ الْغَفُورُ ذُو الرَّحْمَةِ لَوْ يُؤَاخِذُهُم بِمَا كَسَبُوا لَعَجَّلَ لَهُمُ الْعَذَابَ بَل لَّهُم مَّوْعِدٌ لَّن يَجِدُوا مِن دُونِهِ مَوْئِلاً} (الكهف: 58)

58- Your Lord forgives sins and He is of ample mercy, and if He had punished the disbelievers in the world by their bad deeds, He would have hastened the torment for them as they deserve it. However, they have an appointment, which is the Resurrection and Reckoning Day, and they shall not find a resort or escape therefrom.