Let us now explain this point in modern language. The Shi'ah scholars say that those who deny the existence of Imams with all their characteristics, in reality belittle Islam. An expert invariably accompanies technical equipment when it is sent somewhere. When a country like America or the Soviet Union dispatches technical equipment like a phantom or a combat aircraft to a country the people of which are not conversant with that equipment, it always sends some experts also along with it. Of course in the case of such simple arms as the textiles experts are not required. Now what do you think about Islam which has come from Allah? Do you consider it to be a simple thing for which no experts are required or regard it as a complex equipment which when issued, is always accompanied by technical experts who train people at the receiving end till they become conversant with it.
An Imam means an expert in religious affairs - a real expert who does not make a mistake and does not fall into any error. The Holy Prophet brought Islam to the people. It was necessary that at least for some time Divine experts should be present among the people to acquaint them with it.
The Holy Prophet appointed a competent person to undertake this responsibility. The Shi'ah scholars call this appointment a Divine favour, for it was beneficial for humanity. As humanity must proceed towards Allah, His benevolence requires that He should show His favour to it. Just as Prophethood is a Divine favour, similarly Imamate also is a Divine favour. This may be called a rational proof of Imamate, a cardinal principle of the Shi'ah creed.
Infallibility
Here the question of infallibility arises. The Shi'ah believes that an Imam is the custodian and protector of Islamic law. It is through him only that people can know Islam. The Shi'ah believes that an Imam is as infallible as the Holy Prophet, whose infallibility is beyond all doubts. If we know for certain that the Holy Prophet has made a particular statement, we can never doubt its veracity. We can never say that the Holy Prophet has made a mistake. It is unimaginable that one sent by Allah for the guidance of the people needing guidance would ever make a mistake or commit a sin. A Prophet cannot disobey Allah knowingly and intentionally.
For example, if Allah wants a Prophet to convey a certain message to the people, the Prophet cannot change it on the plea that it does not suit his personal interest. To do so would be against the very nature of Prophethood.
If it is admitted that Imamate is something supplementary to Prophethood for the purpose of expounding religion, then it becomes certain that the existence of an Imam is a must, and that an Imam is infallible for the same reason for which a Prophet is infallible.
If somebody says that the infallibility of an Imam is not so essential, because if an Imam makes a mistake, it is possible that some other person brings the mistakes to his notice, we would say that in that case that other person would again require somebody else to keep a watch on him, and so on. At the final end we would certainly need a protector of Islamic law who may be infallible. Further, should an Imam do something wrong, it would be the duty of others to guide him a right, while the people's duty is to follow him, not to guide him. These two things are not consistent with each other.
source : www.tebyan.net
