Severity of deception in religious matters

وَمَنْ أَظْلَمُ مِمَّنِ ٱفْتَرَىٰ عَلَى ٱللَّهِ ٱلْكَذِبَ وَهُوَ يُدْعَىٰٓ إِلَى ٱلْإِسْلَـٰمِ ۚ وَٱللَّهُ لَا يَهْدِى ٱلْقَوْمَ ٱلظَّـٰلِمِينَ

And who is more unjust than one who invents about Allāh untruth while he is being invited to Islām. And Allāh does not guide the wrongdoing people.