There is no verse in the Qur’an that condones fighting any peaceful non-Muslim on the sole ground that he/she is a non-Muslim. The Qur’an expressly prohibits compulsion in religion [2:256]
If anyone calls himself a Muslim and his actions are contrary to the teachings of
Islam, then you cannot blame the faith. If you may be aware, The Lords Resistance Movement which claim to fight for the Christian faith massacred thousands of innocent people in Uganda in order to put in place, a government based on the Bibilcal Ten Commandments. In Ireland, the Irish Republican Army was a Catholic group which carried out various acts of terrorism in the UK killing scores of people.

Are you going to blame Christianity for these macabre and terrorist acts? Come please be objective about these things.