Ahadith on killing those who leave Islam
(Muslim apostates being hanged. Courtesy shariaalert.com)
Islam is very clear on what is to be done to those who leave Islam (i.e., apostates). They must be killed. Every single school and scholar of Islam agrees on this issue. This principle is inviolable since, like almost all of Islam, it can be traced back to Muhammad.
Here are two ahadith (plural of Hadith) which talk of Muhammad's death sentence on those who left Islam. Both are from the Hadith collection that almost all muslims rank the highest of the six canonical Hadith collections - Hadith Sahih Bukhari.
Hadith Sahih Bukhari
Volume 9, Book 84, Number 57:
Some Zanadiqa (atheists) were brought to 'Ali and he burnt them. The news of this event, reached Ibn 'Abbas who said, "If I had been in his place, I would not have burnt them, as Allah's Apostle forbade it, saying, 'Do not punish anybody with Allah's punishment (fire).' I would have killed them according to the statement of Allah's Apostle, 'Whoever changed his Islamic religion, then kill him.'"
The next Hadith is even more interesting because it clarifies Islam's position on those people who simply chose to revert back to their original faith. In the following Hadith, a Jew who had temporarily converted to Islam (perhaps under duress) and chose to return to his original religion, is killed.
Hadith Sahih Bukhari
Volume 9, Book 84, Number 58:
Narrated Abu Burda:
Behold: There was a fettered man beside Abu Muisa. Mu'adh asked, "Who is this man?" Abu Muisa said, "He was a Jew and became a Muslim and then reverted back to Judaism." Then Abu Muisa requested Mu'adh to sit down but Mu'adh said, "I will not sit down till he has been killed. This is the judgment of Allah and His Apostle (for such cases) and repeated it thrice. Then Abu Musa ordered that the man be killed, and he was killed. Abu Musa added, "Then we discussed the night prayers and one of us said, 'I pray and sleep, and I hope that Allah will reward me for my sleep as well as for my prayers.'"
There is absolutely no dissension within Islam on this issue. It was a little surprising to me that one of the things about the program "Undercover mosque" that shocked viewers was that the Islamic teacher instructed her students thus:
"What do we do if someone leaves Islam? We kill him. Kill him."
This is not surprising - it is simply the law of Islam, and something all muslim schools agree upon.
Islam is a one-way street. You can (and everyone eventually must, on pain of death) enter Islam.
But you can't ever leave.
PS: Sounds very much like Islamic marriages from the male point of view. The male is free to divorce his wife by simply repeating "I divorce you" thrice. But if the woman tries to leave her abusive husband, she is beheaded.