In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Allaah (The Most High) said:
فَمَنْ أَظْلَمُ مِمَّنْ كَذَبَ عَلَى اللَّهِ وَكَذَّبَ بِالصِّدْقِ إِذْ جَاءَهُ أَلَيْسَ فِي جَهَنَّمَ مَثْوًى لِلْكَافِرِينَ
Then, who does more wrong than one who utters a lie against Allah, and denies the truth [this Qur’an, the Prophet (Muhammad ), the Islamic Monotheism, the Resurrection and the reward or punishment according to good or evil deeds] when it comes to him! Is there not in Hell an abode for the disbelievers? [Soorah Zumar: Ayah:32]
There is none that is more oppressive than the one who fabricates a lie against Allaah by attributing to him that which is not befitting for him, like setting up partners along with him and attributing to him a son or he says I have received revelation and absolutely nothing was revealed to him. And there is none that is more oppressive than the one who rejects the truth that which has been revealed to Muhammad صلى الله عليه وسلم . Is not the fire a final abode and a dwelling place for those who disbelieve in Allaah and those who do not believe in Muhammad صلى الله عليه وسلم and they do not act according to what he came with; certainly it is! [Source: Tafseer Muyassar, with the supervision of Shaikh Saaleh Aala Shaikh]