The Sunnah essentially means the creed and beliefs (aqeedah) which is why many Imam of as-salaf 1 (predecessors) and khalaf named their aqeedah books “Sharh as-Sunnah” e.g, As-Sunnah by Imam Ahmed, Usool as-Sunnah by Imam Ahmed, Sharh Usool as-Sunnah by Abdullah bin Imam Ahmed, Sharh as-Sunnah by Imam al-Barbahaari, Sharh as-Sunnah by Imam al-Muzini, Usool as-Sunnah by Imam al-Humaydi and many others. None of these books dealing with issues of sunnah of eating, drinking or sitting etc. All of these books are belief books that relate to us the correct manhaj (methodology) of ahl-us-sunnah.
Prophet ﷺ said on the authority of Abu Hurairah (may Allāh be pleased with him)
افْتَرَقَتِ الْيَهُودُ عَلَى إِحْدَى أَوْ ثِنْتَيْنِ وَسَبْعِينَ فِرْقَةً وَتَفَرَّقَتِ النَّصَارَى عَلَى إِحْدَى أَوْ ثِنْتَيْنِ وَسَبْعِينَ فِرْقَةً وَتَفْتَرِقُ أُمَّتِي عَلَى ثَلاَثٍ وَسَبْعِينَ فِرْقَةً
The Jews were split up into seventy-one or seventy-two sects; and the Christians were split up into seventy one or seventy-two sects; and my community will be split up into seventy-three sects.Sunan Abi Dawood 4596 (Hasan), Jami` at-Tirmidhi 2640 (Hasan)
There are additional words in another narration where Prophet ﷺ also gave us a strong warning
كلُّهم في النَّارِ إلَّا ملَّةً واحِدةً ، قالوا : مَن هيَ يا رسولَ اللَّهِ ؟ قالَ : ما أَنا علَيهِ وأَصحابي
All of them are in fire except one sect, they said who is that (sect) O Messenger of Allāh? He ﷺ said, that which me and my companions are uponJami` at-Tirmidhi 2641 (Classed as Hasan by Imam al-Albāni)
Abdullah Ibn Mubārak said:
The foundation of 72 sects of innovation come from 4 foundational sects from the people of desires / innovation.
So, whoever prefers Abu Bakr, Umar, Uthmān and `Ali [may Allāh be pleased with them] (in terms of virtues) above all other Sahaba of Prophet ﷺ and does not mention the rest of the companions except with goodness then he is free from Al-Shia’ sect, completely.
And whoever agrees that faith implies statements and actions (and not only statements) and agrees that the faith increases with obedience and decreases with disobedience, then he is free from Al-Irjā (being from Al-Murjia), completely.
And whoever agrees that the prayer is valid behind every muslim imam, whether he is a persistent sinner, or a pious person, and that Jihad is valid with any khalifah (caliph), and does not see it permissible to revolt against the ruler and makes du’ā for them, then he is free from the ways of Al-Khawārij, completely.
And whoever agrees that the destiny is all from Allāh , the good and the bad one, He ﷻ guides whomsoever He wills and misguides whomsoever He wills, then he is free from the ways of Al-Qadariyah, completely and he is from the people of Sunnah. End Quote 2
These statement of Abdullah Ibn Mubārak are the clear signs to distinguish beween a person of sunnah and person of bid’ah.
- If you see a person who speaks ill of Uthmān or Mu’awiyyah (may Allāh be pleased with both of them) or rejects Uthmān’s caliphate then this person is not from the ahl-us-sunnah rather a rafidhi. He might have a hidden agenda and might come up to you pretending to be from ahl-us-sunnah.
- If a person rejects the action or rejects that a person’s action has any thing to do with his faith or he claims that imān (faith) is, in reality, there or not there and does not increase or decrease, then know that this person is a murji and not from the person of Sunnah.
- If a person rejects praying behind some leaders and rulers or believes that it is allowed to revolt against a ruler (in form of demonstrations or using war tactics / swords) or does not make du’ā for them (for their rectification or guidance), then know that this person is a khāriji and not upon the manhaj of the Prophet ﷺ or manhaj of as-salaf, regardless of what he claims.
- Whoever affirms for Allāh what He affirmed from Himself in His Book (the Noble Qurʾān) or from the blessed tongue of His Messenger ﷺ and rejects what Allāh negated for Himself in His Book or from the blessed tongue of His Messenger ﷺ without distorting the text or re-interpreting it, nor making any resemblance of it with creation and accepts whatever comes in all the authentic narrations, and he believes whatever comes from Allāh in it’s apparent form with apparent meaning then he is safe from the deviant groups of Rhetoric (Kalaam), completely.
- Whoever worships Allāh upon that what He has legislated; and what Prophet ﷺ did; without increasing or decreasing anything from it and sticks to the methodology of the salaf in belief, speech and actions, then he is free from the innovation, completely.
These are the foundational differences that distinguishes people of sunnah and people of bid’ah.
Stick to the sunnah however difficult it be and learn your religion and the blessed way of our beloved Prophet ﷺ and his companions (may Allāh be pleased with all of them).