Quran 2:217 — The Heifer (Al-Baqarah)

They ask you about the Sacred Months and fighting therein: say, "Fighting therein is a sacrilege. However, repelling from the path of GOD and disbelieving in Him and in the sanctity of the Sacred Masjid, and evicting its people, are greater sacrileges in the sight of GOD. Oppression is worse than murder." They will always fight you to revert you from your religion, if they can. Those among you who revert from their religion, and die as disbelievers, have nullified their works in this life and the Hereafter. These are the dwellers of Hell, wherein they abide forever.

[2:216] Fighting may be imposed on you, even though you dislike it. But you may dislike something which is good for you, and you may like something which is bad for you. GOD knows while you do not know.

[2:218] Those who believe, and those who emigrate and strive in the cause of GOD, have deserved GOD's mercy. GOD is Forgiver, Most Merciful.