Insulting religion is considered an apostasy from the viewpoint of the Islamic Shari`ah, may Allah forbid, if the slanderer means what he says and is aware of the gravity of that. But if he does not understand the consequence of his words due to sheer ignorance or if he does not mean to insult the religion itself, at this case, he is not considered an unbeliever. Nevertheless, he still incurs a grave sin, which entails that one needs to seek Allah’s forgiveness, pronounce the two Testifications of Faith (saying that there is no god but Allah and Muhammad is the Messenger of Allah) and thus renewing his commitment to Islam.
The Kuwaiti Encyclopedia of Fiqh, states the following: Muslim jurists have unanimously agreed that whoever curses the religion of Islam is considered a disbeliever. A person who insults a Muslim’s (commitment to) religion is considered by the Hanafi jurists as a disbeliever. Nevertheless, cursing the religion of a certain person may be construed as picking fault in his bad morals and abominable treatment, rather than the religion of Islam in itself. Thus, such insult does not amount to disbelief. The erudite Muslim scholar,`Illaish, states, “Many common people, such as donkey and camel drivers and domestic servants fall into this crime of cursing the religion. anyone who indulges in this grave sin, intending by his insult the Shari`ah of Islam and the rulings ordained by Allah to govern His servants, is considered a disbeliever. Then, if he persists in that and even shows what indicates that he means insult, then he is considered an apostate.”
The eminent Muslim scholar, Dr. Husam al-Din Ibn Musa `Afana, a professor of Principles of Islamic Jurisprudence at Al-Quds University, Palestine, states: Unfortunately, cursing religion is one of the worst phenomena prevailing in our Muslim countries. No doubt, those who bear the responsibility of spreading this wrong phenomenon are parents, teachers, etc. They have to shoulder the responsibility of showing people the grave consequences of this evil. Also, there is no doubt that cursing religion or Allah or insulting His Messenger, peace and blessings be upon him, stands as a clear disbelief and an act of apostasy even if the one who indulges in this act claims to be joking. In this regard, Allah, Glorified and Exalted be He, says, (And if thou ask them (O Muhammad) they will say: We did but talk and jest. Say: was it at Allah and His revelations and His Messenger that ye did scoff? Make no excuse. Ye have disbelieved after your (confession of) belief…) (At-Tawbah: 65-66)
Finally, we would like to advise the one who indulges in this act to hasten to Allah, seeking His forgiveness and reverting to the straight path so that Allah may forgive him. And the one who hears any person saying that should hasten to denounce it and forward repentance to Almighty Allah.