Quran 6:108 from Surah Al-An'aam on Divine Marvels.
وَلَا تَسُبُّواْ ٱلَّذِينَ يَدۡعُونَ مِن دُونِ ٱللَّهِ فَيَسُبُّواْ ٱللَّهَ عَدۡوَۢا بِغَيۡرِ عِلۡمٖۗ كَذَٰلِكَ زَيَّنَّا لِكُلِّ أُمَّةٍ عَمَلَهُمۡ ثُمَّ إِلَىٰ رَبِّهِم مَّرۡجِعُهُمۡ فَيُنَبِّئُهُم بِمَا كَانُواْ يَعۡمَلُونَ
English translation: And (do) not insult those whom they invoke from other than Allah lest they insult Allah (in) enmity without knowledge Thus We have made fair-seeming to every community their deed Then to their Lord (is) their return then He will inform them about what they used to do
Transliteration: wala tasubbu alladhina yad'una min duni al-lahi fayasubbu al-laha adwan bighayri il'min kadhalika zayyanna likulli ummatin amalahum thumma ila rabbihim marji'uhum fayunabbi-uhum bima kanu ya'maluna