Surah Az-Zukhruf (The Ornaments of Gold), Verse 37

وَاِنَّهُمْ لَیَصُدُّوْنَهُمْ عَنِ السَّبِیْلِ وَیَحْسَبُوْنَ اَنَّهُمْ مُّهْتَدُوْنَ ۟

Wa innahum la yasuddoo nahum 'anis sabeeli wa yahsaboona annahum muhtadoon

“Such (evil ones) really hinder them from the Path, but they think that they are being guided aright!”

Quran 43:37 (Yusuf Ali Translation)