In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Shaikh Rabee Bin Haadee Al-Madkhalee [hafidhahullaah] said:
To be mindful of Ahlul Bidah [The people of religious innovations] – to have hatred for them and boycott them- is the correct path of protecting Ahlus Sunnah against falling into their fitnah. And to be lackadaisical about them- to harbour a good suspicion of them and inclining towards them- is the beginning of the path towards misguidance and deviation. [Allaah said:]
وَلَا تَرۡكَنُوٓاْ إِلَى ٱلَّذِينَ ظَلَمُواْ فَتَمَسَّكُمُ ٱلنَّارُ
And incline not toward those who do wrong, lest the fire should touch you. [Surah Hud, Aayah 113]
And who is more unjust than Ahlul Bidah? Ahlul Bidah are more evil than the sinners, and due to this the Faqeeh of Basra and the most intelligent of them- Salaam Bin Abee Mutee [rahimahullaah]- said, “It is more beloved to me that I meet Allaah with the scroll of Hajjaaj than meet Him with the scroll of Amr Ibn Ubaid”.
Amr Ibn Ubaid was a Zaahid and a worshipper Maashaa-Allaah, but he was an innovator and a misguided one, and Hajjaaj was an evil doer, a blood shedder and a criminal. He [Salaam Bin Abee Mutee] held that if he were to make a choice between meeting Allaah with the scroll of Hajjaaj and that of Amr Ibn Ubaid, he would choose to meet Allaah with the scroll of Hajjaaj-the blood shedder and oppressive evil doer. And why is this? [That is] due to his realization regarding the danger and ugliness of bidah.
And it is sufficient for us that the Messenger [sallal laahu alayhi wasallam] described [bidah] in his khutbah as the worst of all affairs, as reported in the Hadeeth of Jaabir [radiyallaahu-anhu]
[Source: An Excerpt from Al-Mawqif As-Saheeh Min Ahlil Bidah. page 12. Slightly paraphrased]