Punishment of Apostates in the Holy Quran

(217) They ask you about the sacred month - about fighting therein. Say, "Fighting therein is great [sin], but averting [people] from the way of Allah and disbelief in Him and [preventing access to] al-Masjid al-Haram and the expulsion of its people therefrom are greater [evil] in the sight of Allah. And fitnah is greater than killing." And they will continue to fight you until they turn you back from your religion if they are able. And whoever of you reverts from his religion [to disbelief] and dies while he is a disbeliever - for those, their deeds have become worthless in this world and the Hereafter, and those are the companions of the Fire, they will abide therein eternally.

(137) 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.

(54) O you who have believed, whoever of you should revert from his religion - Allah will bring forth [in place of them] a people He will love and who will love Him [who are] humble toward the believers, powerful against the disbelievers; they strive in the cause of Allah and do not fear the blame of a critic. That is the favor of Allah; He bestows it upon whom He wills. And Allah is all-Encompassing and Knowing.

(112) And Allah presents an example: a city which was safe and secure, its provision coming to it in abundance from every location, but it denied the favors of Allah. So Allah made it taste the envelopment of hunger and fear for what they had been doing.

(25) Indeed, those who reverted back [to disbelief] after guidance had become clear to them - Satan enticed them and prolonged hope for them.

(32) Indeed, those who disbelieved and averted [people] from the path of Allah and opposed the Messenger after guidance had become clear to them - never will they harm Allah at all, and He will render worthless their deeds.