This nation will divide into 73 sects. All of them are in the hellfire except for one.
The Companions never differed regarding the foundations of this religion. They may have differed about the branches of the religion like certain aspects of the prayer or fasting or marital affairs.
Shaykh al-Islām Ibn Taymīyyah said: Innovations are synonymous to splitting and dividing like the Sunnah is synonymous with unity and the Jamā’ah. So it is said Ahl al-Sunnah wa-al-Jamāʿah as it is said Ahl al-Bidʿah wa-al-Fīrqah (the People of Innovation and Splitting).
Allāh forbade splitting, He said:
وَاعْتَصِمُوا بِحَبْلِ اللَّـهِ جَمِيعًا وَلَا تَفَرَّقُوا ۚ
And hold fast, all of you together to the rope of Allāh and be not divided.
[Sūrah Āl-Imrān, 3:103]
Abū Mūthakar al-Samʿānī said: If you were to gather from the tongues of our scholars and that which was narrated by their salaf and our imāms, it is as if it emanates from a single heart and a single tongue.
تَحْسَبُهُمْ جَمِيعًا وَقُلُوبُهُمْ شَتَّى
You would think they were united, but their hearts are divided.
[Sūrah al-Ḥashr, 59:14]
This is how Ahl al-Bidʿah are: divided and separated.
Ibn Ḥazm (d. 152 AH) said: There is nothing more harmful to the various branches of knowledge and its people than those who enter themselves into it and they are not from it. They are ignorant and they think they have knowledge. They cause corruption whilst they think they are correcting the affairs.
Points of advice: