Surah Al-'Ankabut, verse 1

أَحَسِبَ ٱلنَّاسُ أَن يُتْرَكُوٓا۟ أَن يَقُولُوٓا۟ ءَامَنَّا وَهُمْ لَا يُفْتَنُونَ ﴿٢﴾

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

وَلَقَدْ فَتَنَّا ٱلَّذِينَ مِن قَبْلِهِمْ ۖ فَلَيَعْلَمَنَّ ٱللَّهُ ٱلَّذِينَ صَدَقُوا۟ وَلَيَعْلَمَنَّ ٱلْكَـٰذِبِينَ ﴿٣﴾

But We have certainly tried those before them, and Allāh will surely make evident those who are truthful, and He will surely make evident the liars.