Islam is the religion of Tawhid (monotheism): Monotheism of Lordship (Tawhid al-Ruboobiya), Monotheism of Worship (Tawhid al-Uloohiya and Ibadah), and uniting all humans in a single body that obeys and worships one God. Unity and Tawhid are fundamental concepts to establishing this Deen. We can not unify our goals without uniting on the principles of this Deen, the methods to establishing it, and on the major and minor aspects of it.
The calls to unite and maintain unity are widespread in the Quran and the Hadith of the Prophet PBUH. This is evidence to the unquestionable importance of unity and that its significance in Shariah. It is evidence to the importance of averting conflict and avoiding disagreements, since disagreements lead to division.
Allah says: "And hold fast, all together, by the Rope which Allah (stretches out for you), and be not divided among yourselves" (3:103)
وَاعْتَصِمُواْ بِحَبْلِ اللّهِ جَمِيعًا وَلاَ تَفَرَّقُواْ
"That ye should remain steadfast in Religion, and make no divisions therein" (42:13)
أَنْ أَقِيمُوا الدِّينَ وَلَا تَتَفَرَّقُوا فِيهِ
"Nor did the People of the Book make schisms, until after there came to them Clear Evidence." (94:4)
وَمَا تَفَرَّقَ الَّذِينَ أُوتُوا الْكِتَابَ إِلَّا مِن بَعْدِ مَاجَاءتْهُمُ الْبَيِّنَةُ
"Be not like those who are divided amongst themselves and fall into disputations" (3:105)
وَلاَ تَكُونُواْ كَالَّذِينَ تَفَرَّقُواْ وَاخْتَلَفُواْ
Huthayfa ibn Al-Yaman said: people used to ask the Prophet PUBH about Khair (goodness) and I used to ask him about Sharr (evil) in fear of falling in it. So I said "O Messenger of Allah, We used to be in Jahiliya (ignorance) and evil, then Allah SWT sent you to us with goodness (i.e. Islam). So is there evil after this goodness?"
He PBUH answered "Yes."
So I said "So is there goodness after this evil?"
He PBUH answered "Yes, but it is smoky (i.e. not clear)."
So I asked "What is this smoke?"
He PBUH said "People who follow other than my guidance. You acknowledge some of their sayings and reject others."
So I asked "Is there evil after this goodness?"
He PBUH said "Yes, Inviters to the doors of Hellfire; they throw in it whoever answers them."
I said "O Messenger of Allah, describe them for us."
He PBUH said "They have your skin [colour] and speak with your tongues (i.e. language)."
I said "So what do you command me [to do] if I reach them?"
He said "Adhere to the Jama'ah of Muslims and their Imam".
I said "But there's no Jama'ah nor an Imam?"
He said "Disassociate and withdraw from all these sects, even if you have to bite on a tree-truck until death takes you, while you are in that state." (reported in Bukhary).
Ibn Abbas (may Allah be please) with him said: the Messenger of Allah PBUH said "Whoever sees from his Ameer (leader) something that he dislikes, he should be patient because whoever leaves the Jama'ah one bit and dies, then he died a Jahiliya death (like those before Islam)." (reported in Bukhary and Muslim).
Ibn Umar (may Allah be please) said: Umar delivered a sermon one day in al-Jabiya and said: O People, I am standing here in where the Messenger of Allah once stood and he [PUBH] said "I advise you [to care for] my companions, then those who follow them, and those who follow them ... I command you to hold to Jama'ah and I forbid you from division because Satan is with the single one, and he is further away from two. Whoever longs for the comfort of Jannah, then [he must] adhere to the Jama'ah." (reported in Termisie).
In a long Hadith narrated by al-Harith al-Asha'ry that the Messenger of Allah PBUH said "I command you five [things] that Allah commanded me: Hear and Obey [your leader], make Jihad and Hijrah, and [adhere to] the Jama'ah because whoever leaves the Jama'ah one bit, he has removed the neckwear of Islam from his neck unless if he returns." (reported in Termisie).
Abdul Allah ibn Mas'oud narrated that the Messenger of Allah PBUH said "By the One that there's no god but He, forbidden (haram) is the blood of a Muslim who testifies that there's no God but Allah and that I am the Messenger of Allah, except in three [cases]: one who abandons Islam by leaving the Jama'ah, the married adulterer, and a soul of a soul." (reported in Nisa'ay).
Arfaja al-Ashja'ey said: I saw the Prophet of Allah PBUH on the minbar delivering a sermon to the people where he said "There will be, after my [death], things and things. Whomever you see leaving the Jama'ah or wants to divide the Ummah of Mohammad PBUH, whomever it may happen to be, then kill him because the Hand of Allah is upon the Jama'ah and Satan is running with whoever leaves the Jama'ah." (reported in Nisa'ay).
A'awf ibn Malik said: the Messenger of Allah PBUH said "By the one whose Mohammad's soul is in His Hand, my Ummah will divide into seventy three sects, one is in Jannah and seventy two in Hellfire." It was said "O Messenger of Allah, who are they?" He said "the Jama'ah." (reported in Ibn Majah).
Abdul Allah ibn Maso'ud narrated that the Messenger of Allah PBUH said "Three things do not cause the heart of a Muslim to depart [Islam]: sincerity to Allah in performing deeds, sincere advice to the leaders of Muslims, and adherence to Jama'ah since the prayer surrounds them." (reported in Termisie).
Umar ibn Al-Khatab said: the Messenger of Allah PBUH said "whoever has given allegiance (baya'a) to a man without consultation with Muslims, then he should not accept it nor the one giving it in fear that they would both be killed". (reported in Bukhary).
Umar ibn Al-Khatab said: the Messenger of Allah PBUH said "whoever has given allegiance (baya'a) to an Imam, then he has given his handshake and the fruit of his heart. Thus, he should obey him as much as he can. If another comes to remove [the Imam], then cut his throat". (reported in Muslim).
Arfaja al-Ashja'ey said: the Prophet of Allah PBUH said "Whoever comes to you intending to divide you and break your strength after you all agreed on one man, then kill him." (reported in Muslim).
The above verses and hadiths show in their totality that consensus on an Ameer (leader) is obligatory. Since the Jama'ah does not occur without someone in control of managing its affairs. This is also human nature. Baya'a (loyalty and allegiance) is given to whoever Muslims give their allegiance to first, on the condition that he fulfills the conditions set by Shariah. So if someone tries to take it away from him, then the public interest demands that to treat the one causing conflict with the harshest of punishment (i.e. death) in order to preserve the unity of Muslims and avert divisions. The scholars have no disagreement on this issue at all.
Ibn Taymiya said regarding the issue of taking leaders "As for the head of a party that is partial (i.e. a separate party), if they were united on what Allah commanded His Messenger without any addition or subtraction, then they are believers and they have the rights and obligations of believers. But if they added or removed something like favouring those in their party whether rightly or wrongly, and avoiding those not in their party whether rightly or wrongly, then this is a form of division that Allah and His messenger condemned." (Al-Fatawa, Vol. 11 p. 92).
However, these days many Muslims mixed up the rules of High Authority or Khilafa (Rulership), the High Imam (Ruler or Khalifa) and giving allegiance and loyalty (Baya'a) to the Khalifa, which is what is intended in the aforementioned hadiths. Muslims confused these rules with the rules regarding minor authority; such as appointing an Ameer while traveling or carrying a collective action that is mandated by Shariah like enjoining good and forbidding evil, under the umbrella of High Authority. This mix-up was the result of mass confusion after the fall of the Khilafa.
If we imagine that the Khilafa still exists and that Ameer al-Mu'mineen (Ruler or Imam) exists in the capital of the Khilafa, wherever it may happen to be, it would be very difficult to imagine that a group in a particular field of Dawa would expect every Muslim to give allegiance to them and join their membership. This would be considered a rebellion against the original allegiance to the Khalifa, which carries the consequences mentioned in the hadiths. To clarify this point, let's take a look at another example.
Groups and Assemblies, under the umbrella of Khilafa, would be established to serve a specific role within the general context of the greater Islamic State. These groups would end when they've completed their role. Hence, they have no right to force anyone to join their ranks (because then it would be an opposition movement to the established rule). However, since the Khilafa ended and Muslims are no longer bound to a particular Ruler, some Muslims thought that these hadiths apply to the smaller groups and assemblies that serve a particular role in Shariah. Whether their aim was specific such as calling people to leave Bida'a and correcting those who worship graves, or their aim was more general such as uniting the ranks and following a specific methodology to re-establish the Khilafa. The use of the word "Jama'ah" in the names of such groups further misled people to believe that the hadiths require Muslims to be members of one of these "Jama'ahs".
The "Jama'ah" that is intended in the aforementioned hadiths is the Jama'ah that the Messenger of Allah PBUH intended in the Hadith of Ibn Annas: the Messenger of Allah PBUH said "The children of Israel (Jews) split into seventy one sects and my Ummah will split into seventy two sects, all of which are in the Hellfire except one: the Jama'ah." (reported by Ibn Majah). Abu Dawood reported a different narration "[my Ummah] will split into seventy three [sects]."
Hence, the saved sect, the Jama'ah, is the Jama'ah of Muslims in its general meaning; i.e. those who follow the Book of Allah and the Sunnah of His Messenger. It is the Jama'ah of Muslims who are united on the understanding of the Quran and Sunnah as understood by the companions, followers, and the followers of the followers (i.e. the first three generations). This Jama'ah encompasses every individual who:
Believes in and accepts Islam,
Does not commit any act of Shirk
Does not follow a Bida'a in Aqeeda
There's no requirement to being part of this Jama'ah that entails membership in another group or assembly, which aims to enjoin good and forbid evil, establish a Sunnah, or abolish a Bida'a.
The issue of Unity and following an Imam, in its general sense, is a matter that is well-established in Shariah based on evidences, which makes it a principle of Shairah. Playing with the meaning of it and changing its requirements is something that has to be warned against and against those who do this. It is imperative on those who claim that membership in their Jama'ah is what is meant by the aforementioned evidences to review their understanding of the texts and to distinguish between the rules and the applying the rules to specific scenarios or situations.
Another established principle in Shariah is that those who give guidance to the Jama'ah are "أهل الحل و العقد" (People of Authority & Decision). The original evidence to this is the verse "O ye who believe! obey Allah, and obey the Messenger, and those charged with authority among you." (4:59). It was said that those charged with authority are the Rulers, some scholars said they are those with knowledge of Quran and follow the methodology of Ahl As-Sunnah wal-Jama'ah without dissension over any general principle in Shariah or agreement on a Bida'a in Aqeeda. Both of these opinions were given by Imam Nawawi, Ibn Taymiya, Ibn Katheer, and others. There's no discrepancy between the two opinions since both are needed to establish the rule; since obedience to the Rulers without the agreement of scholars is misguidance and obedience to scholars without agreement of Rules leads to weakness and division. The verse also indicates that obedience to those in authority is not independent. If the Rulers and scholars obey Allah SWT and His Messenger, then we are obliged to obey them. But if they do not abide by the Shariah completely, then we are only obliged to obey in what they obey Allah SWT; we do not obey in the rest. People of Authority & Decision exist all over the World. They are those who Allah SWT has given wisdom and knowledge to and have authority in their region.
When the Rule of Shariah was suspended and the High Authority and Imam (Ruler) were lost, the People of Authority & Decision became individuals who have no common assembly to unite them. This segmentation and lack of organization between the People of Authority & Decision under one roof does not prevent them as individuals from being references to the Ummah in issues that affect it.
The religious authority that the People of Authority & Decision enjoy as individuals, in the absence of a Ruler (Imam), is of higher rank and authority than those leaders of Jama'ahs claim. Furthermore, obedience and loyalty to People of Authority & Decision is of greater importance than obedience and loyalty to any group or leader; unless this leader is known for his knowledge and piety, then he's at best one of the People of Authority & Decision. Hence, loyalty to him is limited to the aims of his group and it is up to the discretion of every Muslim to either join or not. But the group remains as not having any obligation on or authority over anyone outside of its membership who is part of the Jama'ah in its general sense (i.e. the majority of Muslims).
What we concluded in this article does not by any means compromise the need and importance of having groups that work toward establishing one or more set principles of Shariah in the lives of Muslims. Such Jama'ahs are necessary sometimes to forbid the bad and enjoin the good, in the absence of a High Authority. It is only required to know the limitations of such Jama'ahs and the leaders of such organizations over the members of their groups. We have to watch carefully our actions so as not to replace a false practice (Munkar) with another one.