O you who believe! If you obey a group of those who were given the Scripture…..
Allaah (The Most High) said:
يَا أَيُّهَا الَّذِينَ آمَنُوا إِنْ تُطِيعُوا فَرِيقًا مِنَ الَّذِينَ أُوتُوا الْكِتَابَ يَرُدُّوكُمْ بَعْدَ إِيمَانِكُمْ كَافِرِينَ
”O you who believe! If you obey a group of those who were given the Scripture, they would (indeed) render you disbelievers after you have believed!” [3:100]. That is because of their envy and hatred towards you (believers), and their extreme eagerness to turn you away from your religion, just as He (The Most High) said:
وَدَّ كَثِيرٌ مِنْ أَهْلِ الْكِتَابِ لَوْ يَرُدُّونَكُمْ مِنْ بَعْدِ إِيمَانِكُمْ كُفَّارًا حَسَدًا مِنْ عِنْدِ أَنْفُسِهِمْ مِنْ بَعْدِ مَا تَبَيَّنَ لَهُمُ الْحَقُّ
”Many of the people of the Scripture wish that if they could turn you away as disbelievers after you have believed, out of envy from their ownselves, even, after the truth (that Muhammad Peace be upon him is Allah’s Messenger) has become manifest unto them.” [2:109]
[Source: Tayseer Al-Kareem Ar-Rahmaan Fee Tafseer Kalaam Al-Mannaan of Imaam as-Saa’di (rahimahullaah)]