Allah said,

وَمَنْ أَظْلَمُ مِمَّنِ افْتَرَى عَلَى اللَّهِ الْكَذِبَ وَهُوَ يُدْعَى إِلَى الإِسْلاَمِ

(And who does more wrong than the one who invents a lie against Allah, while he is being invited to Islam) meaning, none is more unjust than he who lies about Allah and calls upon rivals and associates partners with Him, even while he is being invited to Tawhid and sincerely worshipping Him. This is why Allah said,

وَاللَّهُ لاَ يَهْدِى الْقَوْمَ الظَّـلِمِينَ

(And Allah guides not the people who are wrongdoers.) Allah said,

يُرِيدُونَ لِيُطْفِئُواْ نُورَ اللَّهِ بِأَفْوَهِهِمْ

(They intend to put out the Light of Allah with their mouths.) indicating that the disbelievers will try to contradict the truth with falsehood. Their attempts are similar to one's attempt to extinguish the sun with his mouth, which is impossible. Likewise is the case of their attempt to extinguish truth. So Allah said,

يُرِيدُونَ لِيُطْفِئُواْ نُورَ اللَّهِ بِأَفْوَهِهِمْ وَاللَّهُ مُتِمُّ نُورِهِ وَلَوْ كَرِهَ الْكَـفِرُونَ - هُوَ الَّذِى أَرْسَلَ رَسُولَهُ بِالْهُدَى وَدِينِ الْحَقِّ لِيُظْهِرَهُ عَلَى الدِّينِ كُلِّهِ وَلَوْ كَرِهَ الْمُشْرِكُونَ

(But Allah will bring His Light to perfection even though the disbelievers hate (it). He it is Who has sent His Messenger with guidance and the religion of truth to make it victorious over all (other) religions even though the idolators hate (it).) We explained the meanings of similar Ayat before, in the Tafsir of Surah Bara'ah. All praise and thanks are due to Allah.