Surah Al-Baqarah (The Cow), Verse 120

وَلَنْ تَرْضٰی عَنْكَ الْیَهُوْدُ وَلَا النَّصٰرٰی حَتّٰی تَتَّبِعَ مِلَّتَهُمْ قُلْ اِنَّ هُدَی اللّٰهِ هُوَ الْهُدٰی وَلَىِٕنِ اتَّبَعْتَ اَهْوَآءَهُمْ بَعْدَ الَّذِیْ جَآءَكَ مِنَ الْعِلْمِ مَا لَكَ مِنَ اللّٰهِ مِنْ وَّلِیٍّ وَّلَا نَصِیْرٍ ۟

Wa lan tardaa 'ankal Yahoodu wa lan Nasaaraa hattaa tattabi'a millatahum; qul inna hudal laahi huwalhudaa; wa la'init taba'ta ahwaaa'ahum ba'dal lazee jaaa'aka minal 'ilmimaa laka minal laahi minw waliyyinw wa laa naseer

“Never will the Jews or the Christians be satisfied with thee unless thou follow their form of religion. Say: "The Guidance of Allah,-that is the (only) Guidance." Wert thou to follow their desires after the knowledge which hath reached thee, then wouldst thou find neither Protector nor helper against Allah.”

Quran 2:120 (Yusuf Ali Translation)