sincerity of belief

وَيَخِرُّونَ لِلْأَذْقَانِ يَبْكُونَ وَيَزِيدُهُمْ خُشُوعًا ۩

And they fall upon their faces weeping, and it [i.e., the Qur’ān] increases them in humble submission.

أَحَسِبَ ٱلنَّاسُ أَن يُتْرَكُوٓا۟ أَن يَقُولُوٓا۟ ءَامَنَّا وَهُمْ لَا يُفْتَنُونَ

Do the people think that they will be left to say, "We believe" and they will not be tried?