Pointing out the error in which al-Tahawi fell in his book "Al-'Aqidah al-Tahawiyyah" regarding the issue of faith, and clarifying the position of the Salaf in that matter.

The Shaykh : "Abu Ja'far al-Tahawi" (may Allah have mercy on him), in this book, followed the methodology of the scholars of the Salaf who preceded him and those who came after him, such as the two Shaykhs mentioned earlier, except in the issue of faith; for in that, he adopted the position known today as the Maturidiyyah, which is the position of "Abu Hanifah" (may Allah have mercy on him); where he held that faith does not increase or decrease. Here is a matter that must be addressed; because it has confused some of the students. Some of the partisans of the Hanafi school, without their partisanship for the Salafi school, claimed that there is no essential difference between what "Abu Ja'far al-Tahawi" held in this issue and what the Salaf and those who followed their path held in the issue of faith. They said, or claimed, that there is no essential difference, but rather it is a verbal difference. In reality, they are pointing to a matter of subtlety; which is that when the scholars of the Salaf include righteous deeds in the term "faith," they do not make righteous deeds a condition of perfection that is a complete condition in faith; such that if this condition is absent, faith is absent. Rather, they make righteous deeds a condition of perfection, not a condition of validity, unlike the Khawarij who declare as disbelievers those who commit a major sin. And committing a major sin, without doubt, contradicts righteous deeds. Accordingly, they declare as disbelievers those who commit major sins. As for the Salaf, they do not declare as disbelievers those who commit major sins, but they make that a cause for a deficiency that occurs in his faith.
So the disagreement between the people of hadith and the Salaf and those who followed their path, and the Hanafis in this issue, is not actually essential; because when the Hanafis say: righteous deeds are not part of faith, they mean that it is not a condition of validity. As for it being a condition of perfection, that is where the disagreement lies. The Hanafis do not agree with the Khawarij, as the Salafis do, both in the past and present. But they differ from them in another point, and here lies the subtlety I referred to; for they agree with the Salafis that righteous deeds are not a condition of perfection, but are not a condition of validity. However, they differ from them in the statement of the Salafis, the people of complete tawhid (the oneness of Allah), that faith increases and decreases; its increase is righteous deeds, and its decrease is evil deeds. The Hanafis—that is, the Maturidiyyah—say: faith is not a thing that increases or decreases. It is a fixed reality, with no difference between the most pious of people and the most sinful of people; as long as they share in the faith whose locus is the heart.
Here is the reality of the disagreement between the Hanafis and the Salafis, both in the past and present. As for them not making righteous deeds a pillar in faith; here they agree with the Salafis. But this does not mean that they do not differ with them in that faith increases and decreases. This is a belief known from the Salaf and circulated among them. As for the Hanafis, they hold what you have heard, that faith does not increase or decrease.
This is a point that must be noted for whoever reads "Al-'Aqidah al-Tahawiyyah" by "Abu Ja'far al-Tahawi" (may Allah have mercy on him). In this issue only, he opposed the methodology of the Salaf. As for the rest, we encourage Muslims to read this creed with the aid of understanding it through "Sharh Ibn Abi al-'Izz al-Hanafi," for he explained the book according to the methodology of the righteous Salaf. This is what is easy to mention from the books to which one should refer who wants to take the creed of tawhid (the oneness of Allah) safe from every blemish and foreign element.