The following are further details why the prophets must be infallible.

The following are further details why the prophets must be infallible. 1. The Principle of Instruction. It is obvious that the purpose of sending prophets was to educate people, and that in teaching the teacher's behaviour is a more effective instrument than his speaking and verbal instruction.

The habits and deeds of the teacher can bring about a radical transformation in man due to people’s tendency to imitate, one of the indisputable fact in the working of the mind, man gradually adopts the manner and conduct of his teacher, and becomes of the same colour so that it is as if he is the clear, limpid surface of a pool which reflects the image of the sky above him.

Speech alone cannot play the part of instruction, rather it serves instruction, and this is the idea of the prophetic mission, that prophets must possess praiseworthy habits and qualities and be untainted with sin and error so that they can effectively attract the people of this world towards the sacred aim.

It is clear that one who has soiled his hands with sin, even though in secret and without anyone being aware so that he himself remains pure in the eyes of his fellow men, will never have that unwavering strength of mind to bring about a radical transformation in the area of the human spirit. One who taints his lips with wine can never dissuade others from drinking it, and raise the voice of truth and establish an iron will in combating this act.

The intense discomfort and disquietude of the prophets, and especially the noble prophet of Islam, about the sins and indecencies of people is itself the best witness to the fact that they were disgusted with every evil and were not involved in sins at all. The great secret in the progress of the prophets was the consistency in their words and deeds, and it is this harmony which enabled them to transform the fundamentals of human thought and lead societies toward more meaningful cultural values.