Quran 61:10-12 – “O You who believe! Shall I guide you to a commerce that will save you from a painful torment. That you believe in Allah and His Messenger (Muhammad ), and that you strive hard and fight in the Cause of Allah with your wealth and your lives, that will be better for you, if you but know! (If you do so) He will forgive you your sins, and admit you into Gardens under which rivers flow, and pleasant dwelling in Gardens of ‘Adn – Eternity [‘Adn (Edn) Paradise], that is indeed the great success.”
As I have pointed many times before, to fight in God’s way, does not endorse killing of the innocent. These passages always exhort people to fight tyranny, oppression and persecution. To fight in God’s way could also mean, strive to preach the Message of Islam verbally. These verses below show the beauty of what ‘Fight in His (God’s) way’ means,
Quran 2:190 Fight in the way of God those who fight you but do not transgress. Indeed. God does not like transgressors.
Quran 2:246 “Would you perhaps refrain from fighting if fighting was prescribed for you?” They said, “And why should we not fight in the cause of Allah when we have been driven out from our homes and from our children?” But when fighting was prescribed for them, they turned away, except for a few of them. And Allah is Knowing of the wrongdoers.
Quran 4:75 And what is [the matter] with you that you fight not in the cause of God and [for] the oppressed among men, women, and children who say, “Our Lord, take us out of this city of oppressive people and appoint for us from Yourself a protector and appoint for us from Yourself a helper?”