A hadith in Sahih al-Bukhari reports the Prophet Muhammad (peace and blessings be upon him) as saying "Whoever changed his Islamic religion, then kill him." Critics say Islam has no freedom of religion.
“Whoever changed his Islamic religion, then kill him.”Sahih al-Bukhari 6922, grading: Sahih (in Sahih al-Bukhari). English translation as given on sunnah.com
All the classical Sunni and Shia schools of law held that the penalty for a Muslim who apostatized was death, and that only the ruler could carry it out, never an individual. Dr. Jonathan Brown sets this out plainly in his Yaqeen Institute paper before explaining what it meant.
There shall be no compulsion in [acceptance of] the religion. The right course has become distinct from the wrong. So whoever disbelieves in ṭāghūt and believes in Allah has grasped the most trustworthy handhold with no break in it. And Allah is Hearing and Knowing.Quran 2:256, Sahih International
Indeed, those who have believed then disbelieved, then believed then disbelieved, and then increased in disbelief - never will Allah forgive them, nor will He guide them to a way.Quran 4:137, Sahih International
And say, "The truth is from your Lord, so whoever wills - let him believe; and whoever wills - let him disbelieve." Indeed, We have prepared for the wrongdoers a fire whose walls will surround them. And if they call for relief, they will be relieved with water like murky oil, which scalds [their] faces. Wretched is the drink, and evil is the resting place.Quran 18:29, Sahih International
The Quran sets no worldly punishment for leaving Islam. It warns of consequences in the next life (Quran 2:217), and it describes people who believe, then disbelieve, then believe again, then disbelieve again (Quran 4:137), which assumes they are still alive between those changes.
“It is not permissible to take the life of a Muslim who bears testimony (to the fact that there is no god but Allah, and I am the Messenger of Allah, but in one of the three cases: the married adulterer, a life for life, and the deserter of his Din (Islam), abandoning the community.”Sahih Muslim 1676, grading: Sahih (in Sahih Muslim). English translation as given on sunnah.com
In the early community, ridda meant a public act of political secession: leaving the community and joining its enemies at a time when religion and political loyalty were one. The Prophet's own wording joins leaving the religion with abandoning the community. Brown notes that there is no reliable evidence that the Prophet ever executed anyone for apostasy alone, as the scholar Ibn al-Talla of Cordoba observed. When Ubaydallah ibn Jahsh became a Christian in Ethiopia, the Prophet did not order him punished, and the Treaty of Hudaybiyya allowed anyone who left the Muslims for Mecca to go unharmed.
“A bedouin gave the Pledge of allegiance to Allah's Messenger for Islam. Then the bedouin got fever at Medina, came to Allah's Messenger and said, "O Allah's Messenger! Cancel my Pledge," ... The bedouin finally went out (of Medina)”Sahih al-Bukhari 7211, grading: Sahih (in Sahih al-Bukhari). English translation as given on sunnah.com
The caliph Umar rebuked commanders who had executed six apostates, saying he would have imprisoned them or offered them a way back. Umar ibn Abd al-Aziz allowed recent converts in Iraq who left Islam to return to their earlier protected status. Modern scholars such as Mahmud Shaltut and Yusuf al-Qaradawi concluded that what the law punished was not disbelief but fighting and subverting the Muslim community, comparable to treason, and Brown argues that Muslim governments today may rightly set the punishment aside.
If your brother, the son of your mother, or your son, or your daughter, or the wife of your bosom, or your friend, who is as your own soul, entices you secretly, saying, “Let us go and serve other gods,” which you have not known, you, nor your fathers; you shall not consent to him, nor listen to him; neither shall your eye pity him, neither shall you spare, neither shall you conceal him; but you shall surely kill him. Your hand shall be first on him to put him to death, and afterwards the hands of all the people. You shall stone him to death with stones, because he has sought to draw you away from Yahweh your God, who brought you out of the land of Egypt, out of the house of bondage.Deuteronomy 13:6, 8, 9, 10, World English Bible (public domain)
The Torah commands that even a brother, son, daughter, wife or closest friend who privately invites someone to worship other gods must be stoned, with the relative's own hand first upon them. This is a penalty for private religious persuasion, with no condition of rebellion or war. Jews and Christians today do not apply it and explain it by the setting of ancient Israel. The Islamic law of ridda, which was tied to public secession and enforced only by the state, should be read with at least the same attention to its setting.
Quran quotations: Sahih International via quran.com. Hadith quotations: the English translations and gradings shown on sunnah.com. Bible quotations: World English Bible (public domain).