Surah Aali Imran (The Family of Imran), Verse 100

یٰۤاَیُّهَا الَّذِیْنَ اٰمَنُوْۤا اِنْ تُطِیْعُوْا فَرِیْقًا مِّنَ الَّذِیْنَ اُوْتُوا الْكِتٰبَ یَرُدُّوْكُمْ بَعْدَ اِیْمَانِكُمْ كٰفِرِیْنَ ۟

Yaaa ayyuhal lazeena aamanoo in tutee'oo fareeqam minal lazeena ootul Kitaaba yaruddookum ba'da eemaanikum kaafireen

“O ye who believe! If ye listen to a faction among the People of the Book, they would (indeed) render you apostates after ye have believed!”

Quran 3:100 (Yusuf Ali Translation)