Infallibility of the prophets
Almighty Allah selected the prophets so that they may entrust the human beings with laws and life-giving program of religion in a perfect way without adding or subtracting anything. That they may show man the straight path of perfection and divine proximity and it is one path and not more. And also that they may help human beings on the path of salvation and perfection; that they take up the responsibility of guardianship and leadership of nation and implementation of divine laws and development of excellence of man.
Responsibility of the prophets in this regard is explained in three stages:
1. They receive laws and programs of religion through the channel of revelation;
2. They convey the divine programs and messages to human beings;
3. They themselves act on the rules and regulations of religion and also call people to divine religion through their words and deeds.
The aim of Almighty Allah in sending mortal prophets assures that they should be infallible in these three stages; that is they should be immune from mistakes, doubts and forgetfulness in receiving the divine messages and conveying them to the people. In case they are not infallible, how can they convey the life-giving program of religion without any alteration and without any increase or decrease to people? In that case would the aim of the wise God in sending the prophets be achieved perfectly? Can people gain satisfaction and assurance that the statements of the prophets are the same message of God and program of religion? No, it is never in this way, on the contrary divine prophets should be immune from errors, doubts and forgetfulness so that they may be able to convey the programs of religion without any increase or decrease and that they may guarantee the fulfillment of the aim of Almighty Allah.
Prophets in the stage of acting on the laws of religion also must be infallible; that is they should fulfill the duties and obligatory acts and keep away from prohibited matters, sins and evil deeds. Because they are perfect examples of religion and by their actions they call people to good deeds and restrain them from evil deeds. If the prophets are not infallible, how can they take up the responsibility of guiding the humanity and how they can invite people to good deeds?
People do not trust one who is himself deviated and who is having contradiction between his words and deeds; since they say: If he was truthful and had believed in his own words, he would have acted according to them. In that case most probably they would prefer to follow their acts and not their words (supposing they were not in consonance with their prophethood). Therefore Almighty Allah will never send such a person as a prophet.
Hence the intellect of man testifies to the necessity of infallibility of prophets and there is no need to quote more verses of Quran or traditions to emphasize this matter. But in the coming pages we would quote some of them by way of textual proofs.
Philosophy of infallibility
In the past discussion we concluded that prophets are immune from sins, mistakes and forgetfulness. Now the question arises that what is the philosophy of infallibility? Why some people are infallible and why some are not? Since all human beings are prone to commit mistakes, how can some persons be immune from errors? What factor bestows to human beings such a power and immunity that they can dominate their selfish desires and don’t even think of committing sins? What is the real motive and aim of this immunity?
According to our belief, infallibility is a quality of the soul and a powerful inner capacity, which restrains the infallible from committing sin and falling into doubt and other similar things. The factor and aim of the existence of this quality is perfect faith, which is beyond the stage of meaning and mental imagination and which has come into the shape of a certainty and actual realization. People who have reached to the lofty stages of knowing Almighty Allah and have faith in resurrection and through the inner conscience have witnessed the greatness and majesty of the Lord of the universe; and who are aware of the effects of deeds, good manners as also the consequences of following bad ethics and character are aloof from sins and disobedience and with insight and from the aspect of choice and intention, they were obedient to divine laws and control their selfish desires and under no circumstances cross the divinely ordained limits of servitude and submission.
On the other hand, the existence of this insight is a strong support, which prevents them from committing mistakes and forgetfulness in receiving divine revelation and in conveying them to the people. They have realized the truth of divine messages and possess the treasures of unseen knowledge. It is due to this same reason that they are immune from mistakes and errors.
Since the existence of such a perfect and infallible man is necessary for prophethood, Allah, the Mighty and Sublime has arranged the system of creation in such a way that when needed, such a person would be available.
It is said that although the prophet is infallible and does not commit any kind of sin, it is not that the capacity of committing sins has been taken away from him. Instead, the prophet is also like other people; he is capable enough to commit sins and has the choice to commit them; at the most, under the influence of a strong faith and perfect insight, which is placed in his being as a divine gift, by choice and intention he gives up evil deeds and does not fall into divine disobedience.
Below we present some examples of strong evidences which prove that it is necessary for divine prophets to be infallible:
Almighty Allah says in the Holy Quran:
عَالِمُ الْغَيْبِ فَلَا يُظْهِرُ عَلَى غَيْبِهِ أَحَداً / إِلَّا مَنِ ارْتَضَى مِن رَّسُولٍ فَإِنَّهُ يَسْلُكُ مِن بَيْنِ يَدَيْهِ وَمِنْ خَلْفِهِ رَصَداً / لِّيَعْلَمَ أَن قَدْ أَبْلَغُواْ رَسِالاَتِ رَبِّهِمْ وَأَحَاطَ بَمَا لَدَيْهِمْ وَ أَحْصَى كُلَّ شَىْءٍ عَدَدًا
“The Knower of the unseen! so He does not reveal His secrets to any. Except to him whom He chooses as an apostle; for surely He makes a guard to march before him and after him. So that He may know that they have truly delivered the messages of their Lord, and He encompasses what is with them, and He records the number of all things.” (72:26-28)
Allamah Tabatabai has written under the exegesis of this verse:
Apparently this verse shows that Almighty Allah has chosen the prophets for divine revelation and also gave them a hidden power which accords protection to them. It is that Almighty Allah has surrounded the prophets in order to guard revelation from destruction and change which Satan or others may undertake. This is due to the joining of prophethood to the stage of manifestation. Similar to this verse is the verse in which it is mentioned in the words of angels:
(And we do not descend but by the command of your Lord; (Know that) to Him belongs whatever is before us and whatever is behind us and whatever is between these, and your Lord is not forgetful.)
The verses prove that divine revelation from the beginning of revelation till the time it reaches to the ears of man are in protection and are guarded from every kind of alteration.
Also it has come in the same background that
أُوْلَئِكَ الَّذِينَ هَدَى اللَّهُ فَبِهُدَيهُمُ اقْتَدِهْ
“These are they whom Allah guided, therefore follow their guidance.” (6:90)
This proves the infallibility of the prophets; thus all of them are guided and Allah says:
مَن يُضْلِلِ اللَّهُ فَمَا لَهُ مِنْ هَادٍ
“…and (as for) him whom Allah makes err, there is no guide for him.” (39:23)
وَمَن يَهْدِ اللَّهُ فَمَا لَهُ مِن مُّضِلٍّ
“And whom Allah guides, there is none that can lead him astray.” (39:37)
And He also says:
مَن يَهْدِ اللَّهُ فَهُوَ الْمُهْتَدِى
“Whomsoever Allah guides, he is the one who follows the right way.” (7:178)
Thus Almighty Allah has kept immune His guided ones from every deviated and all kinds of deviations, which want to gain an upper hand on them. That is He has kept them safe from every kind of disobedience since disobedience is also a kind of misguidance.
 Al-Mizan, Vol. 2, Pg. 139
 Al-Mizan, Vol. 2, Pg. 140