What does the following verse imply:

وَلَوْ جَعَلْنَاهُ قُرْآنًا أَعْجَمِيًّا لَّقَالُوْا لَوْلَا فُصِّلَتْ آيَاتُهُ أَأَعْجَمِيٌّ وَعَرَبِيٌّ قُلْ هُوَ لِلَّذِينَ آمَنُوْا هُدًى وَشِفَاء وَالَّذِيْنَ لَا يُؤْمِنُوْنَ فِيْ آذَانِـهِمْ وَقْرٌ وَهُوَ عَلَيْهِمْ عَمًى.

 Had We sent down this Qur’an in a language other than Arabic, they would have objected: “Why are not these verses explained in detail? [A Book in] a non-Arabic [tongue] and [the addressees] Arabs. Tell them: “It is a guidance and healing for those who believe. And for those who believe not, there is a deafness in their ears and a blindness in their eyes.” (41:44)

The Qur’an goes on to assert that it is guidance and healing for those who have made themselves worthy of it by accepting faith. People who do not profess faith in it are a victim of their own evil nature. It is not that the Book has some deficiency that they refuse to believe in it. It is their own addiction to evil that has made them blind and deaf to its message.