Distinction between sincere believers and disbelievers

وَجَآءَ ٱلْمُعَذِّرُونَ مِنَ ٱلْأَعْرَابِ لِيُؤْذَنَ لَهُمْ وَقَعَدَ ٱلَّذِينَ كَذَبُوا۟ ٱللَّهَ وَرَسُولَهُۥ ۚ سَيُصِيبُ ٱلَّذِينَ كَفَرُوا۟ مِنْهُمْ عَذَابٌ أَلِيمٌ

And those with excuses among the bedouins came to be permitted [to remain], and they who had lied to Allāh and His Messenger sat [at home]. There will strike those who disbelieved among them a painful punishment.