In The Name of Allaah, The Most Merciful, The Bestower of Mercy.

Al-Allaamah Rabee Bin Haadi Al-Madkhali [may Allaah preserve him] said: Allaah [The Most High] said:

يَا أَيُّهَا الَّذِينَ آمَنُوا إِن تُطِيعُوا فَرِيقًا مِّنَ الَّذِينَ أُوتُوا الْكِتَابَ يَرُدُّوكُم 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]

The disbelievers and [a group among] the people of the scripture wish that the Muslims should turn away from their Religion.  [Also] the people of Bidah have a great share of this evil intention and desire against those people upon [uprightness]. And for this reason they are to be warned against severely.  [Al-Mawqif As-Saheeh Min Ahlil Bid’ah pages 9-10]