Preserving the Uṣūl
A brief account of the uṣūl (foundations) of ʿaqīdah, the emergence of Ahl al-Sunnah, the various deviant sects and the obligation to refute them.
And know that most of the innovations connected to ’uloom (sciences) and acts of worship occurred in this Ummah at the end of the period of the Rightly Guided Caliphs.
Shaykh Muḥammad ibn Ṣālih alʿUthaymīn
The Messenger of Allāh (ṣallallāhu ʿalayhi wa-sallam) explained clearly to the people – completely and clearly – what their Lord had revealed for them; both the detailed matters and the important ones., the apparent matters and the hidden ones, to such an extent that he (ṣallallāhu ʿalayhi wa-sallam) taught them what they needed to know with respect to matters of eating, drinking, marriage, clothing and housing. So he taught them the etiquette of eating, drinking and relieving one’s self; the etiquette of marriage; the etiquette of clothing and of entering and leaving the house, just as he taught them what they needed to know with regard to the worship of Allāh – the Mighty and Majestic – such as: purification, Prayer, zakāt (alms), fasting, Pilgrimage (Ḥajj) and other than this.
He taught them what they needed to know with regard to the social behaviour with the people, such as kindness to parents, keeping ties of kinship, good companionship with friends and neighbours and other than this. He taught them how to conduct themselves in matters of buying and selling, pawning, leaving deposits, leasing, renting, giving and receiving donations, and other such matters, to such an extent that Abū Dharr (raḍī Allāhu ʿʿʿanhu) said, ‘‘Indeed the Messenger of Allāh (ṣallallāhu ʿalayhi wa-sallam) passed away and there is not a bird flapping its wings in the sky, except that he mentioned to us some knowledge about it.’’ 
FOUNDATIONS OF THE RELIGION:
Salmān al-Faarisee (raḍī Allāhu ʿʿʿanhu) narrated that it was said to him, ‘Your Prophet taught you everything, even how to relieve yourselves?’ So he said to them, ‘‘Yes indeed! And he has prohibited us from facing the qiblah (direction of Prayer) whilst relieving ourselves…’’  Along with this, he taught them the foundation of all these acts of worship, manners and social interractions. This foundation being what the worshippers hold as ʿaqīdah (belief) concerning Allāh – the deity who is worshipped and who alone deserves to be worshipped – regarding His Dhaat (Essence), His Names, His Attributes and His Actions; and what follows from this with regards to His universal Laws and His prescribed Laws, which is based upon His ultimate Wisdom and utmost Mercy. The Companions learnt all of this from the Prophet (ṣallallāhu ʿalayhi wa-sallam) clearly and without any ambiguity, and all of this was built upon the complete Tawḥīd of Allāh (to single out Allāh alone for worship), having as its foundations two great pillars: Affirmation and Negation. As for Affirmation, then it is affirming what is due to Allāh – the Most High – from the rights of His Lordship, worship and His Names, Attributes and Actions. As for Negation, then it is negating any partners to Allāh – the Most High – in all that is due to Him.
THE PEOPLE OF THE SUNNAH:
Those who followed them in goodness (i.e. in ʿaqīdah and manhaj) from those who reached the period of the Companions, or those who came after them from the Imāms of guidance – who deserved the Pleasure of Allāh – remained upon this path – as Allāh – the Most High – said: ‘‘This first to embrace Islām from the Muhaajireen (those who migrated from Makkah to al-Madīnah) and the Ansār (those who lived in al-Madīnah and aided them after migration) and those who follow them in goodness (correct ʿaqīdah and manhaj). Allāh is well-pleased with them, as they are well-pleased with Him. He has prepared for them gardens underneath which rivers flow, to dwell therein forever. This is the supreme achievement.’’ [Sūrah al-Tawbah 9:100]
Then they were followed by those who came later, being blind to the truth. So they went astray and led others astray; either due to inabilities and shortcomings, or due to enmities and oppression. They innovated into the Religion of Allāh – the Most High – that which did not belong to it, in matters of ʿaqīdah (beliefs), ’ʿibādah (acts of worship) and sulook (manners). They did this by either altering the texts of the Book and the Sunnah; and if it were possible, they rejected them entirely!
BRIEF HISTORY OF THE INNOVATED SECTS:
Shaykh al-Islām Ibn Taymīyyah (d.728H) – raḥimahullāh – said:
‘‘And know that most of the innovations connected to ’uloom (sciences) and acts of worship occurred in this Ummah at the end of the period of the Rightly Guided Caliphs; just as the Prophet (ṣallallāhu ʿalayhi wa-sallam) informed, when he said, ‘‘Those of you who live long after me will see a great deal of differences. So hold fast to my Sunnah and the Sunnah of the Rightly Guided Caliphs after me…’’  So when the period of the Rightly Guided Caliphs has passed and the rule of kingship appeared, deficiencies appeared in the leaders, and therefore deficiencies also appeared amongst the people of knowledge and Religion. So during the end of the rule of ʿAlī (raḍī Allāhu ʿʿʿanhu) the innovation of the Khawārij  and the Rāfidah  appeared; and what was connected to this from the actions and Sharīʿah rulings.
The kingship of Muʿāwiyah was a kingship of mercy, to when it passed, the rule of Yazīd came and fitnah (trial, discord) took place within it: the killing of Husayn in ’ʿIrāq, the fitnah of the people of Hurrah in al-Madīnah and the siege of Makkah when ʿAbdullāh Ibnuz-Zubayr took his stand. Then Yazīd passed away and the Ummah split up. Ibnuz-Zubayr in the Hijaaz, the tribe of Hakam in ash-Shaam (Syria, Jordan and Palestine) and the jump to power of Mukhtaar Ibn Abī ’ʿUbayd and others in ’ʿIrāq. All of this took place at the end of the period of the Companions, when there only remained the likes of ʿAbdullāh Ibn ʿAbbās, ʿAbdullāh Ibn ʿUmar, Jābir Ibn ʿAbdullāh, Abū Saʿīd al-Khudrī and others. The innovation of the Qadariyyah  and the Murjī‘ah  then occurred and it was refuted by those Companions who remained, as they had, along with others, refuted the innovation of the Khawārij and the Rāfidah. Indeed, the status of the first three generations is – by agreement of the majority – the best and most just of generations.
So the majority of the Companions had passed away by the end of the rule of the four Rightly-Guided Caliphs – until none remained from the people of Badr, except a few. The majority of the Tābi’īn had passed away in the last period of the younger Companions, during the reign of Ibnuz-Zubayr and ʿAbd al-Malik. The majority of the third generation passed away in the last part of the Umayyah rule, at the beginning of the ʿAbbāsee rule.
It then occurred that many of the offices of authority and power started to be occupied by the non-Arabs, whilst at the same time, many of the Arabs left the offices of power. Some of the non-Arab books were translated into al-ʿArabīc: the books of the Persians, the Indians and the Romans. Thus, what the Prophet (ṣallallāhu ʿalayhi wa-sallam) said, appeared, ‘‘Then lies will become widespread, to such an extent that a person will testify and will not have been asked to do so, and will take an oath without being asked to do so.’’  Then three matters occurred: ra‘yee (opinion), kalām (philosophical speech and theology) and tasawwuf (Ṣufism). The innovation of the Jahmiyyah  also occurred – which is negating and denying the Attributes of Allāh – as well as its opposite which is tamthīl (resembling Allāh to His creation)…Indeed, having knowledge of the foundations of things and their fundamental principles, and having knowledge of the Religion and its fundamentals; and the principles which emanate from it, is the greatest and most beneficial knowledge. Since, if a person does not encompass the knowledge of the reality of things – of which he is in need – keeps thorns in his heart.’’ 
A BRIEF SUMMARY:
Imām Ibn al-Qayyim (d.751H) – raḥimahullāh – said:
‘‘The innovation of the Qadariyyah started at the end of the period of the Companions. So those that remained at that time, such as ʿAbdullāh Ibn ʿUmar, Ibn ʿAbbās and their like, opposed and refuted it. Then the innovation of the Murjī‘ah occurred, after the period of the Companions, so those of the major tābiʿīn who faced it, refuted it. Then came the innovation of the Jahmiyyah after the passing away of the tābiʿīn. Its evil reached alarming proportions and the matter had become dire during the age of the Imāms such as Aḥmad (d.241H) and those with him. There appeared after this, the innovation of hulool (incarnation), this appeared with, and in the time of al-Ḥajjaaj. So whenever Shayṭān brought about an innovation from amongst these innovations, or from other than them, Allāh established those from His Party and Amry, who refuted it and warned the Muslims against it – all of the sake of sincerity and sincere advice to Allāh, His Book, His Messenger and the people of Islām.’’ 
COMPILATION OF THE ʿAqīdah:
And al-Ḥāfiẓ Ibn Ḥajar (d.852H) – raḥimahullāh – said: ‘‘From that which occurred was: compilation of ḥadīth, then tafsīr, then the compilation of the issues of fiqh (jurisprudence) emanating from pure opinion, and then the compilation of matter relating to the actions of the heart. As for the first matter, it was opposed by ʿUmar, Abū Mūsá and a few others whilst the majority allowed it. As for the second, it was opposed by a group from amongst the tābiʿīn, such as Imām ash-Sha’bee (d.104H). As for the third, then it was opposed by Imām Aḥmad (d.241H) and a small group. Imām Aḥmad’s opposition of this intensified."
Also from that which occurred was the compilation of the sayings about Uṣūlud-Dīn (fundamentals of the Religion). Some embarked to affirm it (i.e. the Attributes of Allāh), whilst others negated it. The former went to the extent of making tashbīh (resembling Allāh to His creation), whilst the latter went to the extent of making ta’teel (denying the Attributes of Allāh). The rejection of this from the Salaf – such as Abū Ḥanīfah (d.150H), Abū Yūsuf (d.182H) and al-Shāfiʿī (d.204H), and their sayings with regards to the censuring the people of kalām (philosophical speech and theology) is well known. The reason for such censure was that the people of kalām spoke about the matters which both the Prophet (ṣallallāhu ʿalayhi wa-sallam) and his Companions remained quiet about it. It is established from Mālik (d.179H) that there did not exist at the time of the Prophet (ṣallallāhu ʿalayhi wa-sallam), nor that of Abū Bakr or ʿUmar, anything from these desires – meaning: the innovation of the Khawārij, the Rāfidah and the Qadariyyah. Indeed, those who came after the first three excellent generations expanded upon matters which the Imāms of the tābiʿīn and those who followed them, rejected.
The people of Kʿalám did not content themselves, until they filled the Religion with issues and the sayings of the philosophers. They made this philosophy the basis and the foundational principle to which everything was referred back to, and that which opposed it from the narrations (of the Prophet (ṣallallāhu ʿalayhi wa-sallam) and the Companions and the Salaf who followed them) then ta‘weel (false interpretation) was made of them, even if they were averse to the result. Nor did they content themselves with just this. They claimed that what they had compiled was the oldest branch of knowledge and the most deserving to be acquired; and that those who did not use what the had laid down, then they were from the laymen and ignorant ones. So delight is for the one who clings to what the Salaf were upon, and distances himself from the innovations that the khalaf (the late-comers who opposed the ʿaqīdah and manhaj of the Salaf) introduced. However, if one cannot keep away from it, then let him take only that which he needs and let the way of the Salaf be his intended goal.’’ 
REFUTING THE FALSEHOOD:
It is from the ultimate wisdom of Allāh to make an opposition to the truth, so that by it, the correctness of the truth over falsehood can be made clear. Indeed, the purity of gold does not become apparent except by exposing it to fire. Allāh – the Magnificent and Majestic – through His complete power, vast mercy and the overwhelming strength has sent those who will disprove the evidences of the ones who oppose the truth, and who will refute and make clear the false doubts.
Imām Aḥmad (d.241H) – raḥimahullāh – said:
‘‘All praise is for Allāh, who in every age and interval between the Prophets, raises up a group from the People of Knowledge, who call the misguided to guidance and patiently bear ill-treatment and harm. With the Book of Allāh, they give life to the dead, and by the Light of Allāh, they give sight to the blind. How many a person killed by Iblīs have they revived. How many people astray and wandering have they guided. How beautiful their effects have been upon the people, and how vile people have been towards them. They expel from the Book of Allāh the alterations of those going beyond bounds, the false claims of the liars and the false interpretations of the ignorant ones – those who uphold the banner of innovation and let loose the trials and discords, who differ about the Book, oppose the Book and agree to oppose the Book. Those who speak about Allāh and His Book without knowledge, argue about what it ambiguous in the Book, and deceive the ignorant with such ambiguities. We seek refuge in Allāh from the trials of the misguided ones.’’ 
 From the Shaykh’s introduction to his book, Taqreebut-Tadmuriyyah (p. 7-14) – slightly edited.
 Ṣaḥīḥ: Related by Aḥmad (5/153), al-Tiyālisī (no. 479) and at-Ṭabarānī in al-Kabīr (no. 1647). Its isnād is ṣaḥīḥ (authentic).
 Related by Muslim (1/152) and Abū Dāwūd (no. 8)
 Ṣaḥīḥ: Related by Abū Dāwūd (no. 4607) and al-Tirmidhī (no. 2676); it was authenticated by Shaykh al-Albānī in Irwāʾ al-Ghalīl (no. 2455).
 The Khawārij were the first sect in Islām to split away from the way of the Prophet (ṣallallāhu ʿalayhi wa-sallam) and his Companions. They arose in the caliphate of ʿAlī, making khurūj (rebellion) against him, before the arbitration between him and Muʿāwiyah (raḍī Allāhu ʿʿʿanhumā). From their false ʿaqīdah (creed) is: allowing rebellion against the legitimate Muslim ruler – whether pious of wicked, and declaring a Muslim to be a kāfir (disbeliever), due to commission of a major sin. They were described by the Prophet (ṣallallāhu ʿalayhi wa-sallam) as the Dogs of the Hellfire. Refer to al-Maqālātul-Islāmiyyeen (1/168) of Abū al-Ḥasan al-Ashʿarī, al-Bidāyah (8/22-44) of Ibn Kathīr and Fat′h al-Bārī (12/282-302) of Ibn Ḥajar.
 The Rāfidah (the rejectors) are an extreme sect of the Shīʿah who reject Zayd Ibn ʿAlī Ibn al-Husayn due to his refusal to condemn Abū Bakr and ʿUmar (raḍī Allāhu ʿʿʿanhumā). They rapidly deteriorated in ʿaqīdah, morals and Religion – until the present day – where their beliefs are those represented by the Ithnā ’Ashariyyah Shīʿah of ’Iraan. From their false beliefs are: declaring all but three or five of the Companions to be disbelievers, the belief that their imāms have knowledge of the Unseen, past, present and future, considering the imāmah to be one of the main pillars of īmān (faith) and the incompleteness of the Qurʾān. Refer to al-Maqālātul-Islāmiyyeen (1/65), al-Farq baynal-Firaq (no. 21) of ʿAbd al-Qaahir al-Baghdādī and Talbees Iblīs (p. 94-100) of Ibn al-Jawzī.
 The Qadariyyah are the followers of Ma’bad Ibn al-Juhanī, and from their false beliefs are: that Allāh does not have prior knowledge of anything until it comes into existence; that it is people – and not Allāh – who are the creators of their own actions, denying ʿaqīdah (belief) in the Punishment of the Grave, and denying that the authentic ḥadīth is an evidence for the ʿaqīdah, unless it is related in mutawātir (concurrent) form. Refer to al-Milal wa—al-Niḥal (1/72) ash-Shahrastaanee and Sawnul-Mantaq wal-Kʿalám (p. 160) of as-Suyootee.
 The Murjī‘ah are those who reject that actions are a part of īmān (faith), and they say that īmān is affirmation of the heart and statement of the tongue only. The extreme from amongst them limit īmān to belief in the heart only. They also deny that īmān increases and decreases. Refer to al-Maqālāt (1/214) and al-Farq baynal-Firaq (p. 202).
 Ṣaḥīḥ: Related by al-Tirmidhī (4/500)
 The Jahmiyyah are the followers of Jahm Ibn Ṣafwān, who unleashed upon this Ummah the horrific innovation of ta’teel (denial of Allāh’s Attributes) – either directly, or by twisting the meanings: such as twisting the meaning of the Hand of Allāh to mean: His Power and Generosity. They also deny that Allāh is above His creation, above His Throne, as well as holding the belief that Paradise and Hallefire are not ever-lasting. Refer to ar-Radd ’alal-Jahmiyyah of Imām Aḥmad and also al-Dārimī and al-Ibānah (p. 141) of Abū al-Ḥasan al-Ashʿarī.
 Majmūʿ al-Fatāwá (10/354-368)
 Tahdheeb Sunan Abī Dāwūd (7/61) of Ibn al-Qayyim
 Fat′h al-Bārī (13/253) of Ibn Ḥajar al-’Asqʿalánee
 ar-Radd ’alal-Jahmiyyah waz-Zanādiqah (p. 2) of Imām Aḥmad