Likewise, the Qur’an repeatedly states that Muslims, including Prophet Muhammad, can only admonish non-Muslims regarding religious matters .
The Qur’an addresses disbelief more than 150 times, yet man is never given authority to punish the disbeliever. If Islam sanctioned death for apostasy, why does the Qur’an address—but never sanction—worldly punishment for the apostate who repeatedly believes and disbelieves ? As the majority of these verses were revealed in Medina, not Mecca, critics cannot resort to the “argument” of abrogation of earlier Qur’anic verses by later revelations.
Prophet Muhammad’s example corroborates the view that no punishment for apostasy exists in Islam. Once, a Bedouin convert to Islam suffered a fever while in Medina. He asked to be released from his pledge three times and was refused three times. Still, he left Medina unharmed .
The reader may question if a single incident during Prophet Muhammad’s life is sufficient to prove that Islam does not punish an apostate. In fact, not a single instance exists of Prophet Muhammad punishing an individual because they apostatized.
Finally, Islam does not restrict apostasy . Any “punishment” an apostate incurs is a matter between that person and God. The Qur’an is clear: apostasy is not a worldly crime, it is certainly not the “ultimate” crime, apostates are not to be harmed—let alone put to death, and those who choose to leave Islam have every right to do so. Precisely the same principles of freedom of conscience and speech apply to those who would be deemed blasphemers. That is, in Islam, no worldly punishment exists for blasphemy.
 Qur’an 2:257.
 Qur’an 4:64; 6:70-71; 10:109; 11:47; 50:46; 88:22-23.
 Qur’an 2:218; 3:21, 73, 91; 4:138; 5:55, 62, 93, 100; 9:3, 66-68, 74; 16:107; 47:26-27; 63:2-7.
 Qur’an 4:138; 10:100; 18:30.
Murder in the Name of Allah by by Mirza Tahir Ahmad @ http://www.alislam.org/library/books/mna/index.html
The Truth about The Alleged Punishment for Apostasy in Islam An address by
Hadrat Mirza Tahir Ahmad Khalifatul Masih IV @ http://www.alislam.org/library/books/Apostasy-in-Islam.pdf