2:161 Surely they who believe not, and die in their unbelief, upon them shall be the curse of God, and of the angels, and of all men;

2:217 They will ask thee concerning the sacred month, [whether they may] war therein: Answer, to war therein is grievous; but to obstruct the way of God, and infidelity towards him, and [to keep men] from the holy temple, and to drive out his people from thence, is more grievous in the sight of God, and the temptation [to idolatry] is more grievous than to kill [in the sacred months]. They will not cease to war against you, until they turn you from your religion, if they be able: But whoever among you shall turn back from his religion, and die an infidel, their works shall be vain in this world, and the next; they shall be the companions of [hell] fire, they shall remain therein for ever.

4:137 Moreover they who believed, and afterwards became infidels, and then believed [again], and after that disbelieved, and increased in infidelity, God will by no means forgive them, nor direct them into the [right] way.

8:38 Say unto the unbelievers, that if they desist [from opposing thee], what is already past shall be forgiven them; but if they return [to attack thee], the exemplary punishment of the former [opposers of the prophets] is already past, [and the like shall be inflicted on them].

9:66 Offer not an excuse: Now are ye become infidels, after your faith. If we forgive a part of you, we will punish a part, for that they have been wicked doers.

16:106 Whoever denieth God, after he hath believed, except him who shall be compelled against his will, and whose heart continueth stedfast in the faith, [shall be severely chastised]: But whoever shall voluntarily profess infidelity, on those shall the indignation of God [fall], and they shall suffer a grievous punishment.

18:105 These are they who believe not in the signs of their Lord, or that they shall be assembled before him; wherefore their works are vain, and we will not allow them any weight on the day of resurrection.

39:65 Since it hath been spoken by revelation unto thee, and also unto [the prophets] who [have been] before thee, [saying], verily if thou join any partners [with God], thy work will be altogether unprofitable, and thou shalt certainly be [one] of those who perish: