Why an unbeliever is impure?

By: Ayatullah Makarim Shirazi & Ayatullah Ja'far Subhani
Question: What is the logic behind the Islamic point of view that followers of other religions and in short the Kuffar are impure and they cannot keep social contacts with Muslims although in cleanliness they are ahead of some Muslims? Apparently it is wrong to reply that mixing with disbelievers might misguide a Muslim and with their discussion and sayings they might deviate the Muslims and boycotting them would bring them towards Islam. This should be removed as Islam is the religion of broad-minded, it is a religion in which eyes and ears are closed.
Answer: Firstly it is true that Islam is broad-minded faith and not of where eyes and ears are closed, but if the purpose is that Islam belongs to only one group, then naturally it is not so because Islam is the religion of the whole mankind and if the purpose is that broad minded and intellectuals are more acquainted with Islam, then it is true. But this cannot become its proof that Islam turns a nelson's eye towards people with less knowledge or educated people and should not consider their state.
Now we are coming towards the real question. As it has been pointed unbelievers are unclean by a type of spiritual impurity, whose body is also unclean and they are impure, it is to protect the beliefs of people, who very soon accept the effects of others and get astrayed and this is not something new. Preachers have always recommended to the common people to keep away from polluted and astrayed people and after all Islam has announced that unbelievers are impure.
We do consider that Islam under certain conditions gives the permission for economic, business relations but has not given the permission for eating together or in other words Islam wants that Muslims may keep relations with them and make profit and side by side remain protected from their beliefs and ethics, which can reach to the people while intermingling with them.
Here it should be not misunderstood. We are not saying this that broad minded and educated people, who do not fear that by socializing with the unbelievers there will be no danger of going astray, or spoil their ethics, they can stay with them completely and are exempted from the above rule. No, it is not like that. The orders of Islam do not have any special angle for anyone and to be sure that the limits of Shariat are protected. It is necessary that for the generalization of this order be maintained, because if it is not like that, then every person will assume himself to be educated and maintain relations with unbelievers and the laws and orders of the Shariat will be subverted. (Think for a while.)
Many unbelievers do not refrain from impure things like blood, pork and alcoholic drinks; and naturally their whole life is unclean. To remain keep from those impurities Islam has announced that they are najis, so that those Muslims who by intermingling with them have the possibility of becoming impure may remain safe.
Reference: ImamReza.net