بسم الله الرحمن الرحيم
In the name of Allah, the Most Gracious, the Most Merciful
ALWAYS COMPARE TO THE QUR'AN
Someone asked if the people who say that المرتد or apostate (one who believes then leave the faith) must be killed are Islamically correct.
We always refer to the Qur'an which is the first and most accurate reference.
1. The Qur'an says to people who chose other than Islam "لكم دينكم ولى دين" or unto you your religion and unto me mine. This is very clear that people are entitled to their choices. But to this, those so-called scholars say the people have the choice but once choice is made, they cannot change. This is their interpretation and it does not coinside with the meaning of the verse.
2. The Qur'an says "من شاء فليؤمن ومن شاء فليكفر" or whoever chose let him believe and whoever chose to disbelieve, let him disbelieve. This is the freedom of choice given to people by God and cannot be taken away from them. But again, those so-called scholars would say, yes but at the beginning but once choice is made, they cannot change back. And here again their explanation contradicts the verse.
3. Lastly the Qur'an as always does give the absolute and most clear answer. The Qur'an says: امنوا ثم كفروا ثم امنوا ثم كفروا ثم ازدادوا كفرا لم يكن الله ليغفر لهم ان الذين
"Those who believed then left the faith, then believed then left the faith, then became grew increasingly in their disbelief, Allah will not forgive them." - Surat Al Nisa verse 13
Those who believed then left the faith, watch this, they believed then left the faith. If they were killed for what they have done, matter is over, they are gone. No, the verse says those same people returned back to the faith and afterwards, left the faith again. Not only they left the faith, they became increasingly in the disbelief and God did not say should be killed even then, rather He said He will not forgive them. So, it is a matter between the human and his God. Thus, the Qur'an gives no proof of any punishment to be inflected by society for leaving the faith.
Some say but Khalifa Abu Bakr fought and killed people in the war of الردة Redda or apostacy (leaving one’s faith). This incident happened after the death of the Prophet. Some Muslims decided not to pay Zakah. The title of this incident is completely wrong and misleading as it was not apostacy, those people were Muslims but decided to leave out one of the rituals. Even Omar Ibn El khattab the great companion asked Abu Bakr how could he fight people who say لا اله الا الله محمد رسول الله - or there is no God but the one God and Mohamed is His Prophet. They were Muslims and did not really leave their faith. But then, was Abu Bakr wrong in fighting them? No, he was not. Zakah was the blood line for funds to finance the Islamic Umma and withholding it would have hurt the Umma. It became like taxes imposed by the society. If one does not pay his/her taxes, they will be apprehended and if they resisted and fought, they would be fought against.
Lastly, some might say they should be killed as they are considered to be spies. If it was proven in a court of law that they were indeed spies, they should be killed not because they left the faith but because they spied. This becomes the penalty for spying whether the person still has the faith or left it.
One more note, it was not established that the Prophet did kill or ordered the killing of anyone who left his/her faith.
May God guide us all to His right way. Ameen