إِنَّ الَّذِينَ كَفَرُوا سَوَاءٌ عَلَيْهِمْ أَأَنْذَرْتَهُمْ أَمْ لَمْ تُنْذِرْهُمْ لا يُؤْمِنُونَ ( 6 )
6. Verily, those who disbelieve, it is the same to them whether you (O Muhammad Peace be upon him ) warn them or do not warn them, they will not believe.
(As for the disbelievers) who remain firm in their disbelief, (whether thou warn them), instil fear into them by means of the Qur'an, (or thou warm them not) or you do not instil fear into them, (it is all one for them; they believe not), they do not want to believe. It is also said that they will not believe as it is in Allah's knowledge.