contrast between human potential and willful denial

إِنَّ شَرَّ ٱلدَّوَآبِّ عِندَ ٱللَّهِ ٱلَّذِينَ كَفَرُوا۟ فَهُمْ لَا يُؤْمِنُونَ

Indeed, the worst of living creatures in the sight of Allāh are those who have disbelieved, and they will not [ever] believe-