Although the Islamic belief consists of belief in Allah , His Angels, His Books, His Messengers, the Day of Judgement and al-Qada wal-Qadar, both good and bad from Allah , it does not mean to exclude anything else from the belief. Rather, it means that this forms the basis of belief and there are other thoughts which relate to the ‘aqīdah (creed), such as the infallibility of the Prophets which also come under the belief in the prophets. The evidence of the infallibility of the Prophets is a rational evidence and not a textual evidence because the proof of the prophethood of a Prophet and the message of the messenger to whom he has been sent is rational, established by a perceptible miracle.

Although the Islamic belief is said to consist of belief in Allah , his angels, his books, his messengers, the day of judgement and al-Qada wal-Qadar both good and bad are from Allah , it does not mean that nothing else must be believed in. Rather these concepts only form the basis of belief, as there are other thoughts that are linked to the ‘aqīdah, like the infallibility of the prophets, which fall within the category of belief in the prophets.

Evidence for the infallibility of the prophets is rational and not based upon aural reports. This is because the validity of the prophethood of the prophet and the message of the messenger to whom they are sent is rational and is proven by the tangible miracle. The prophet’s infallible nature necessitates it to be rational because it is one of the requirements to verify the prophethood of the prophets and messengers. The mind necessitates that the prophets and messengers are infallible, as it is a pre-requisite for the role of the prophet and messenger in propagating from Allah .

If it were possible to raise doubts about the infallible nature of the prophets even in one issue of law, consequently this would give rise to the emergence of skepticism and vacuums in every other issue. Hence, at that point both the case for prophethood and messengerhood would be meaningless. The evidence that a person is a prophet or a messenger from Allah  means that he is infallible in everything he propagates.

Thus, by necessity he is infallible in his propagation, and the disbelief in this is disbelief in the message that he brought and the prophethood which he was sent with. Therefore, it is necessary that each and every prophet and messenger is infallible from error in the propagation as this is one of the attributes of the prophets. The mind necessitates that these characteristics are present in each and every prophet and messenger.

As for the infallibility of the prophets and messengers from carrying out actions contrary to the prohibitions and commands of Allah , rational evidence requires that they be categorically infallible from doing al-Kabair. Hence, they can not undertake any al-Kabair because this would mean committing sins. Both obedience and sinning are indivisible. Thus, if it were possible for the prophets to sin in their actions, this would also be true in their propagation. However, this contradicts both the prophethood and messengerhood. Therefore the prophets and messengers are infallible from the al-Kabair, just as they are infallible in propagating the message from Allah .

As for infallibility from the minor sins (al-Saghair), there is a difference of opinion between the Ulama. Some say that they are not infallible from them because they do not constitute sinning and others say they are infallible from the minor sins (al-Saghair) because they constitute sinning.

However, the reality is that the prophets are infallible from everything definite that has been both commanded and prohibited for them. In other words, all the Faraids [pl: Fard] (compulsory obligations) and Muharramat [pl: Haram] (prohibitions). They are also infallible from leaving the Wajibaats (compulsory obligations) and from carrying out Haram (prohibited) actions, whether it is a major or a minor sin. In other words, they are infallible from everything and anything called, or confirmed to be a sin.

This is with the exception of the Makruhat, Mandubat which are different, as they are not infallible from these and neither would this constitute a contradiction with the role of prophethood or messengerhood. Thus it is permissible for them to carry out a Makruh action and to leave a Mandoob action, because neither action constitutes a sin. Likewise it also permissible for them to carry out some Mubah actions and abstain from others, as neither categories in all their aspects fall within the concept of sin. These are the pre-requisites and attributes of the prophets and messengers that the mind necessitates.

However, infallibility only becomes an integral part of the characteristics of the prophets and messengers after they receive revelation and become prophets and messengers. Prior to this they are bound by the same laws as the rest of mankind, because as previously mentioned, infallibility is for the prophethood and messagehood only.