At an interfaith gathering at the mosque is it haram or halal to allow a Christian brother to stand in the prayer line with the Muslim brothers and attempt to do the motions?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

The scholars differed in opinion about the permissibility of letting a non-Muslim enter a mosque without a need, like for the purpose of building.

Al-Kharshi of the Maliki School says: "It is forbidden for a non-Muslim to enter any mosque even if the Muslim in charge of it permits him to do so. This is because the Right to let someone enter the mosque is Allah's and nobody can drop it unless there is a necessity like building. But, this opinion contradicts that of the Shafii School."

In fact, the Shafii, Hambali and the Hanafi agree that non-Muslims can enter the mosque. But the former two (Shafii and Hambali) make exception of the Haram mosque while the latter (Hanafi) believe that the non-Muslim may enter any mosque including the Haram one.

As regards the standing of a Kafir in a row between Muslim brothers in prayer, and his performing the actions of the prayer, the correct opinion is that it is not permissible for someone to allow him to do so, let alone inviting him to do so. This is because of the following matters:

1.     Those who are of the opinion that it is permissible for a Kafir to enter the mosque think, however, that it is more appropriate for him not to do so. And nobody said that he can be permitted to perform an act of worship in the mosque.

2.     The acts of worship that he does between the Muslims are either to glorify his religion, which we should not let him to do in our mosques, or to imitate our prayer, and this is considered as degrading the religion of Islam and mocking the greatest of its pillars after the two declarations of faith. Because if he believes Islam is the true religion, then he would not delay embracing Islam, and this implies leaving his religion.

The Fuqaha (Islamic Jurisprudents), may Allah have mercy on them, stated that it is not permissible for a Muslim to continue a prayer that he/she started performing licitly if his/her state of purity is negated (for instance when passing wind), let alone a Kafir who is impure and who does not fulfill any of the conditions of the prayer.

3.     Generally the clothes and the body of a Kafir are unclean (impure), then we should not touch him during the prayer.

To conclude, we should note that it is not appropriate to qualify the Christians as brothers, because brotherhood is in religion, and they are not upon a religion that Allah accepts.

Allah says: "Truly, the religion with Allah is Islam." (Aali Imran 3:19)

Allah further says: "And whoever seeks a religion other than Islâm, it will never be accepted of him, and in the Hereafter he will be one of the losers. (Aali Imran 3:85)

Allah knows best.