While those who convert to Islam are fêted by their fellow believers, the issue of conversion from Islam to another faith is one of the most controversial areas of Islamic law, writes Mary Fitzgerald
The recent case of Abdul Rahman, an Afghan man who faced the death penalty for converting to Christianity until he was judged mentally unfit for trial, drew attention to this highly sensitive issue within the Muslim world.
The debate on apostasy (ridda in Arabic) echoes many of the arguments concerning how Islamic texts should be interpreted in modern times. But much of the debate centres on establishing an appropriate punishment for disowning Islam - the majority of scholars and jurists consider apostasy itself one of the worst crimes for a Muslim.
Most Muslim scholars agree that Christians and Jews should be respected as "people of 'The Book'," that is those who share a common heritage with Islam. They say that Islam favours freedom of belief, frequently quoting the Koran (Al-Baqarah, 2:256): "Let there be no compulsion in religion." There is much disagreement, however, on the limits of that freedom.
In response to a query on one Islamic website, a scholar wrote: "Once a person converts to Islam, he should practise his faith and never change it. If he changes it, it is a major sin. Whether it is punishable by Islamic law is a debatable matter among Muslim scholars.
"Some believe he should be punished because they count this crime as betrayal, while others say that if someone changes his faith and does not challenge the Islamic society, they consider it a private matter between him and Allah, and it is not punishable by the Islamic faith according to their view. However, both opinions agree that it is a sin punishable by Allah and that it is the worst form of sin."
The influential Qatar-based cleric Sheikh Yusuf al-Qaradawi has written: "All Muslim jurists agree that the apostate is to be punished. However, they differ regarding the punishment itself. The majority of them go for killing; meaning that an apostate is to be sentenced to death."
Apostasy is punishable by death in a number of countries, including Saudi Arabia, Yemen, Iran and Sudan. In other Muslim countries, those who convert to another faith run the risk of having their marriage annulled. They also lose custody of their children and all property and inheritance rights.
There is nothing in the Koran that explicitly calls for the killing of apostates. That punishment is drawn primarily from sayings attributed to the Prophet Muhammad, also known as the hadith. The hadith are used as a secondary authority to the Koran when drawing up and interpreting Islamic law, or sharia.
Some scholars have questioned the veracity of the hadith saying most commonly used to support the killing of an apostate - "He who changes his religion should be killed." Others say that it should be interpreted within the context of the time it was recorded. Several scholars insist that punishment for apostates should be carried out by God alone. They point to a verse in the Koran (Nisa Ayah, 48) which refers only to divine retribution: "Those who blaspheme and back away from the ways of Allah and die as blasphemers, Allah shall not forgive them."
One notable scholar in the history of Islamic jurisprudence, Shamsuddeen al-Sarakhshi, has stated: "Renunciation of the faith and conversion to disbelief is admittedly the greatest of offences, yet it is a matter between man and his Creator, and its punishment is postponed to the Day of Judgment."
Others, like Sheikh al-Qaradawi, condone the death penalty in cases where the apostate encourages others to desert their faith: "The death penalty with regard to apostasy is to be applied only to those who proclaim their apostasy and call for others to do the same. Islam lays down this severe punishment in order to protect its unity and the identity of its community." Still others decry any punishment for leaving Islam, citing the Koran (Al-Kahf, 29): "Let he who wishes to believe do so; and let he who wishes to disbelieve do so."