Ecclesiastes 3:3 To every thing there is a season, and a time to every purpose under the heaven: 2 A time to be born, and a time to die; a time to plant, and a time to pluck up that which is planted; 3 A time to kill, and a time to heal; a time to break down, and a time to build up;
Psalm 82:3 Defend the poor and fatherless: do justice to the afflicted and needy. 4 Deliver the poor and needy: rid them out of the hand of the wicked.
To deny the possible need for violence is to deny that our Father in heaven said there is sometimes a need for it... and if we are not prepared to commit ourselves to violence for a defence of the innocent... we will only be the victims of aggressors.
John 15:13 Greater love hath no man than this, that a man lay down his life for his friends.
That doesn't mean to say, "If you're going to kill my friends, just kill me first... and no worries, I won't fight back."
There is a season for ALL things under heaven... sometimes it means fighting for a righteous cause... like protecting people or yourself.