Distinction between true and false faith

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?