2:191
And kill them wherever you overtake them and expel them from wherever they have expelled you, and fitnah is worse than killing. And do not fight them at al-Masjid al- Haram until they fight you there. But if they fight you, then kill them. Such is the recompense of the disbelievers.
2:193
Fight them until there is no [more] fitnah and [until] worship is [acknowledged to be] for Allah . But if they cease, then there is to be no aggression except against the oppressors.
http://islamqa.info/en/22899
Fitnah (disbelief and worshipping of others along with Allaah)
Ibn al-Atheer said: “Fitnah: trial or test… The word is often used to describe tests in which something disliked is eliminated. Later it was also often used in the sense of sin, kufr (disbelief), fighting, burning, removing and diverting.” (
al-Nihaayah, 3/410. Ibn Hajar said something similar in
al-Fath, 13/3).
3:21
Those who disbelieve in the signs of Allah and kill the prophets without right and kill those who order justice from among the people - give them tidings of a painful punishment.
3:22
They are the ones whose deeds have become worthless in this world and the Hereafter, and for them there will be no helpers.
