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

Nowadays many do not consider bidah to be something harmful to the people who adhere to bidah. By Allah, it is a calamity upon those who have reached this state of affairs. His desires lead him to (such a state) that he does not consider bidah as something harmful to those upon bidah, even though the Messenger, peace and blessings of Allah be upon him, said, “The worst of all matters are the newly invented matters (in the religion) and every newly invented matter (in the religion) is a bidah, and every bidah is misguidance.” [Muslim 867]

“The Jews split into seventy one sects, the Christians split into seventy two sects, and this Ummah [i.e. Muslim Ummah] will split into seventy three sects, and all of them will be in the fire except one. They [i.e. the Sahaabah] said, ‘Who are they O Messenger of Allah?’ He said, “Those upon what I and my companions are upon.” [Sahih Al-Jami 5343] [Footnote a]

They [i.e. the saved sect] are the people upon truth – Ahlus Sunnah, the people who adhere to the Qur’an and Sunnah, the enemies of bidah, misguidance, disbelief, shirk and all types of misguidance. They love the truth, and they establish love and hatred based on that. [Marhaban Yaa Talib Al-Ilm page 22]

Footnote a: https://salafidawahmanchester.com/2024/12/28/all-in-the-fire-except-one/