They ask you about the sacred month1 - about fighting therein. Say, "Fighting therein is great [sin], but averting [people] from the way of Allāh and disbelief in Him and [preventing access to] al-Masjid al-Ḥarām and the expulsion of its people therefrom are greater [evil] in the sight of Allāh. And fitnah2 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.
The people ask you, O Prophet, about the law regarding fighting in the sacred months of Dhū Al-Qa‘dah, Dhū Al-Ḥijjah, Muḥarram and Rajab. Say to them: Fighting in these months is a serious offence in the sight of Allah and is detested, just as the idolaters’ preventing from the path of Allah is also disapproved. Blocking the believers’ access to the Sacred Mosque and removing the people of the Sacred Mosque from it is worse than fighting in a sacred month in the sight of Allah. Their idolatry is worse than killing. The idolaters will continue their oppression by fighting you until they turn you away from your path of truth towards their false path, if they are able to. If anyone turns back from the path of Allah and dies disbelieving in Allah, his good actions shall be reduced to nothing and in the Afterlife he will end up in the fire of Hell, where he will live eternally.