The Ruling on Disagreement in the Fundamentals and Branches, and the Clarification of Bid'ah (Religious Innovation)

Question:
The Messenger of Allah (peace and blessings be upon him) informed us that this Ummah (the Muslim community) would split into seventy-three sects. Is this splitting in the fundamentals or in the branches? And what is the good in applying the term bid'ah (religious innovation) to individuals?

Answer:
This disagreement in the fundamentals, this disagreement in the fundamentals, means in 'Aqeedah (creed). As for disagreement in the branches, that does not harm. Disagreement in issues of Fiqh (Islamic jurisprudence) and Istinbat (derivation of rulings) does not harm, and it is not blameworthy. However, we take from the statements of the Fuqaha (jurists) and their Ijtihad (independent legal reasoning) what is established by evidence, or what is closer to the evidence. Disagreement in issues of Fiqh and Istinbat is not blameworthy. What is blameworthy is that we take the Marjuh (weaker position) or take the opinion that matches our desires and our whims, and we leave the Rajih (stronger position) or the opinion that the evidence points to. The prohibited disagreement, which is what is referred to in this Hadith, is disagreement in 'Aqeedah: this one is a Rafidi, this one is a Jahmi, this one is a Mu'tazili, this one is an Ash'ari, this one is a [Zaydi], and this one and this one, and so on. This is the blameworthy disagreement. It is obligatory to adhere to what the Ahl al-Sunnah wa al-Jama'ah (the people of the Sunnah and the community) are upon, from the Companions, the Tabi'un (the generation after the Companions), the blessed centuries, and those who came after them. This is what is obligatory: that we be with the saved sect, the victorious sect. Everyone is in the Fire except one [sect]. This sect is from the Ahl al-Sunnah wa al-Jama'ah, and they are those who were upon what the Messenger of Allah (peace and blessings be upon him) and his Companions were upon. Yes. He (peace be upon him) said: The prevalent [one]. Yes, close to bid'ah.
Bid'ah (religious innovation) is everything that is newly introduced into the religion that is not part of it. This is bid'ah. His saying (peace and blessings be upon him) , so the one who brings a form of worship for which there is no evidence from the Book of Allah or the Sunnah of His Messenger (peace and blessings be upon him), this is bid'ah. It is obligatory to avoid it and stay away from it, and it is obligatory to stay away from the Mubtadi' (innovator) and boycott them, so that their bid'ah and their evil do not spread among the people.