Differences between Maturidis and Ahl as-Sunnah
Question

Please clarify the differences between the ‘aqidah of Salaf and Maturidi. Will the person following the ‘aqidah of the Maturidis not enter jannah?
Praise be to Allah.Who are the Maturidis?
The Maturidis are a kalami (philosophical group ) based on innovation (bid‘ah); they are named after Abu Mansur al-Maturidi. 
In the beginning, their main focus was on using rational and philosophical proof in disputing with their opponents, the Mu‘tazilah, Jahmis and others, in order to prove the fundamentals of Islam and Islamic beliefs. 
The Maturidis went through several stages. They were not known by this name until after the death of their founder, just as the Ash‘aris were not known and did not spread until after the death of Abu’l-Hasan al-Ash‘ari. We can sum up the stages of development in the following four main stages: 
Origin of the Maturidis
The main focus at this stage was intense debates with the Mu‘tazilah. The prominent figure at this stage was Abu Mansur al-Maturidi, whose full name was Muhammad ibn Muhammad ibn Mahmud al-Maturidi as-Samarqandi; he was named after Maturid, which is a place near Samarkand in Transoxiana, where he was born. 
He is regarded as one of the pioneers of the rational school; he did not acquire a great deal of knowledge of Islamic texts and the science of hadith, which is the case with the majority of scholars in the fields of kalam and usul. 
Abu Mansur al-Maturidi was influenced by Jahmi beliefs in many ways, the most significant of which was: the interpretation of texts that speak of some of the divine attributes that are classed as sifat khabariyyah (attributes that are based on texts and cannot be proven by rational thought, such as the divine Countenance, Hand and so on) in a manner other than the apparent meaning. He also came under the influence of the innovation (bid‘ah) and ideas of the Murjiah. 
He was also influenced by Ibn Kullab (d. 240 AH) and his innovation of the concept of divine “self-talk” (al-kalam an-nafsi) 
Development of the Maturidis
This is the stage during which the students of al-Maturidi and those who were influenced by him developed his ideas further, and formed an independent kalami (philosophical) group. The group first appeared in Samarkand, and worked to spread and defend the thought of their shaykh and leader, and wrote books. They followed the madhhab of Imam Abu Hanifah with regard to minor issues of Islam. Thus Maturidi beliefs became more widespread in Samarkand than elsewhere. 
Among the most well-known figures during this stage were: Abu’l-Qasim Ishaq ibn Muhammad ibn Isma‘il al-Hakim as-Samarqandi and Abu Muhammad ‘Abd al-Karim ibn Musa ibn ‘Isa al-Bazdawi. 
Consolidation of Maturidi beliefs
The main feature of this stage was prolific writing of books and compiling of evidence on which the Maturidi beliefs were based. Therefore it was the most important stage in terms of consolidating this school of thought. 
Among the most important figures during this stage were: Abu’l-Ma‘in an-Nasafi and Najm ad-Din ‘Umar an-Nasafi. 
Expansion and spread of the Maturidis
This is regarded as one of the most important stages, in which the Maturidis reached the peak of their expansion and spread. That was due to the support of the Ottoman sultans. Maturidi dominance spread wherever Ottoman dominance reached. So they spread eastwards and westwards in the Arab lands, India, and the lands of the Turks, Persians and Byzantines. 
There were many prominent scholars among them, such as al-Kamal ibn Humam. 
The Maturidis spread and the number of followers increased in India and neighbouring Eastern countries, such as China, Bangladesh, Pakistan and Afghanistan. They also spread in Turkey, the Byzantine lands, Persia and Transoxiana; they still have a strong presence in these countries. 
Differences between the Maturidis and Ahl as-Sunnah

The Maturidis divided the fundamentals of Islam as follows: 


Rational theology (al-ilahiyyat al-‘aqliyyat)” – this refers to what can be proven by reason, and the texts are secondary to that; that includes Tawhid (the Oneness of Allah) and the divine attributes. 
Different issues of religion based on texts (sam‘iyyat shar‘iyyat)”– this refers to matters which, on the basis of reason, we may be certain that they are possible, but there is no rational proof to confirm them or otherwise; that includes Prophethood, the punishment of the grave, and matters pertaining to the Hereafter. However it is worth noting that some of them included Prophethood under the previous heading (“rational theology”). 

It is very clear that what is stated above is contrary to the way of Ahl as-Sunnah wa’l-Jama‘ah, for whom the Quran, Sunnah and consensus of the Sahabah are the sources of knowledge, and that applies to all issues of religion. (That is, they do not divide them into two categories as the Maturidis did.) 
Moreover, they differed from Ahl as-Sunnah wa’l-Jama‘ah in the innovation of dividing the fundamentals of Islam (usul ad-din) into those that are based on rational evidence and those that are based on texts. This idea is based on a false notion, which is that matters of religion and belief may be divided into principles that may be proven by reason and could not be proven by only texts; rather the textual proof with regard to these matters may be regarded as additional evidence that supplements what is indicated by rational evidence concerning these fundamental issues. 

The Maturidis, like other kalami (philosophical) groups such as the Mu‘tazilah and Ash‘aris, discussed the necessity of knowing Allah, may He be exalted, on the basis of reason before studying the texts (of Quran and Sunnah); they regarded that as the foremost duty of any accountable person, and said that there was no excuse for not doing that. Rather they believe that a person would be punished for not doing it, even if that was before any prophets or messengers were sent. Thus they were in agreement with the view of the Mu‘tazilah. This is a view that is evidently wrong, as it contradicts what is proven in the Quran and Sunnah, which show that reward and punishment only come into effect after the sending of Revelation, as Allah, may He be exalted, says (interpretation of the meaning): “And We never punish until We have sent a Messenger (to give warning)” [al-Isra 17:15]. 

Moreover, the correct view is that the first and foremost duty of any human is to affirm the Oneness of Allah (Tawhid), may He be glorified and exalted, and to enter His religion, not to merely know that there is a Creator, because that is something which Allah has instilled in the innate nature of all creatures. 

According to the Maturidis, the concept of Tawhid means affirming that Allah, may He be exalted, is One in His essence and indivisible; One in His attributes, and there is nothing like Him; and One in His actions and no one plays a part with Him in creation. Hence they did their utmost to prove this understanding of Tawhid, which is based on the idea that God, in their view, is the One Who is able to create, using the rational and philosophical arguments and analogies that were produced by the Mu‘tazilah and Jahmis. This is evidence that was refuted by the salaf and imams (leading scholars) and their followers, and by the prominent scholars of kalam and philosophy, who pointed out that the proof presented in the Quran is more sound.
The Maturidis affirmed only eight attributes of Allah, may He be exalted, although they differed on some of the details thereof. These attributes are: life, power, knowledge, will, hearing, seeing, speech and being a Creator.

Other attributes that are indicated by the Quran and Sunnah, the sifat khabariyyah (attributes that are based on texts and cannot be proven by rational thought, such as the divine Countenance, Hand and so on, that have to do with His Essence or His actions), cannot – in their view – be proven on the basis of rational thinking, therefore they denied all of them, and they misinterpreted the texts that refer to them.
Ahl as-Sunnah wa’l-Jama‘ah, on the other hand, believe in the divine names and also in the divine attributes, and they regard them all as tawqifi (i.e., they are to be learned solely from the texts and not through rational thought). They believe in them (the divine names and attributes) by affirming what is mentioned in the texts, without likening Him to any of His creation. They declare Allah to be above any shortcomings or any similarity to His creation in any way, without denying or misinterpreting any of His names or attributes, and they delegate knowledge of the nature of these attributes to Him, affirming His attributes in a manner that befits Allah, may He be exalted. Allah, may He be exalted, says (interpretation of the meaning): “There is nothing like unto Him, and He is the All-Hearer, the All-Seer” [ash-Shura 42:11].

Their (the Maturidis’) view that the true words of Allah are His “self-talk” that is ever present with Him, and that it is not heard, and that whatever is heard is nothing but an outward manifestation of His eternal self-talk led them to the conclusion that whatever Mushafs are in circulation among the people are to be regarded as created. Thus they ended up embracing the view of the Mu‘tazilah, which is contrary to scholarly consensus; there are abundant reports from the scholars that this view is wrong and, in fact, the one who says that the Quran is created is to be deemed a kafir (disbeliever).
The Maturidis say concerning the definition of faith that it is belief in the heart only. Some of them added that it is verbal affirmation, but they do not believe that it may increase or decrease. They also said that it is haram to say “In sha Allah (if Allah wills)” with regard to being a believer, and that Islam and Iman (faith) are synonymous, with no difference between them. Thus they are in agreement with the Murji’ah on that score, and they differed with Ahl as-Sunnah wa’l-Jama‘ah, because faith, according to the latter, is belief in the heart, words on the lips and physical actions; it increases when one does acts of obedience and decreases when one sins. 
They affirmed that (the believers) will see Allah, may He be exalted, in the Hereafter, but they denied any direction and any face to face meeting. This is a contradictory view as it affirms something and then goes back and denies its reality. 

For more information on this topic, please see: 

al-Mawsu‘ah al-Muyassarah fi’l-Adyan wa’l-Madhahib wa’l-Ahzab al-Mu‘asirah, 1/95-106
al-Maturidiyyah – Master’s thesis, Ahmad ibn ‘Awad-Allah al-Luhaybi al-Harbi
al-Maturidiyyah wa Mawqifuhum min Tawhid al-Asma wa’s-Sifat, Master’s thesis, Shams al-Afghani as-Salafi
Manhaj al-Maturidiyyah fi’l-‘Aqidah, Dr. Muhammad ibn ‘Abd ar-Rahman al-Khamis
Al-Istiqamah by Shaykh al-Islam Ibn Taymiyah
Majmu‘ Fatawa wa Rasail al-‘Uthaymin, 3/307-308 

The fate of the followers of the Maturidi ‘aqidah
It cannot be said regarding the follower of Maturidi ‘aqidah that he will go to Paradise or go to Hell; rather they are like other ordinary Muslims; even though they believe in some innovated views, their innovation (bid‘ah) does not constitute kufr. Hence they are, in general terms, like other Muslims:
“It will not be in accordance with your desires (Muslims), nor those of the people of the Scripture (Jews and Christians), whosoever works evil, will have the recompense thereof, and he will not find any protector or helper besides Allah.
And whoever does righteous good deeds, male or female, and is a true believer in the Oneness of Allah (Muslim), such will enter Paradise and not the least injustice, even to the size of a Naqira (speck on the back of a datestone), will be done to them.” [an-Nisa 4:123-124] 
With regard to their innovation (bid‘ah), that varies from one to another of them; some base their views on misinterpretation or conclusions reached after putting in a great deal of effort, so they may be excused; others are mistaken in their approach in such a way that they may be blamed for it, so they are ultimately subject to the will of Allah – if He wills He will punish them and if He wills He will forgive them. 
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said, after discussing a group of leading Ash‘ari scholars: 
“Moreover, there is not one of those scholars but he put praiseworthy efforts into serving Islam, doing good deeds, refuting the views of many heretics and innovators, and supporting many of those who follow the Sunnah and are religiously committed, as is clear to anyone who is aware of their situation and speaks of them on the basis of knowledge, truthfulness, justice and fair-mindedness. 
But because they got confused when they embraced this principle that they originally adopted from the Mu‘tazilah, even though they are virtuous and wise people, they had no choice but to persist in it and accept its implications. Thus because of that they developed views that Muslims of knowledge and religious commitment had to object to. Because of that, people divided into two groups concerning them: 
Some people respected them, because of their good qualities and virtues; others condemned them because of the views that they developed on the basis of innovation and falsehood. 
But the best approach in all matters is the middle approach (i.e., being fair and acknowledging both good and bad). 
The errors that they fell into are not limited to these people only; other people of knowledge and religious commitment also fell into similar errors. Allah, may He be exalted, accepts good deeds from all His believing slaves, and He overlooks their bad deeds:
“Our Lord! Forgive us and our brethren who have preceded us in Faith, and put not in our hearts any hatred against those who have believed. Our Lord! You are indeed full of kindness, Most Merciful.” [al-Hashr 59:10] 
No doubt if a person tries hard to seek the truth and learn his religion on the basis of the teachings of the Messenger (blessings and peace of Allah be upon him) and makes some mistakes in that, Allah will forgive his mistakes, in fulfilment of the supplication that Allah answered for His Prophet and the believers, when they said: “Our Lord! Punish us not if we forget or fall into error” [al-Baqarah 2:286].
If anyone follows his speculations and his whims and desires, then starts to condemn on that basis those who differ with him because of some matters that they got wrong, thinking that they were right after putting effort into it, and their mistake may constitute an innovation that is contrary to the Sunnah, then he should give the same treatment, or more or less, to those whom he respects and follows. It is very rare that any scholar amongst the later scholars is free of such mistakes, because there is a great deal of confusion and uncertainty, and because people are (chronologically) far removed from the source of Prophetic light by means of which one attains right guidance and dispels confusion and doubt from his heart.” (Dar Ta‘arud al-‘Aql wa’n-Naql, 2/102-103)
And Allah knows best.