You just cannot kill everybody who doesn't agree with you. You can't do it. You'll kill enough of them, and pretty soon, you'll be down to the nitty gritty that is just you guys, and then you'll start disagreeing with each other... In other words, you cannot get to where you want to be by pushing against what you do not want - it never, ever works.
I'm taking this metaphorically to include killing people in my mind, arguing with them, telling them they're wrong, making laws against their beliefs, punishing them, trying to control them.... For anytime I condemn war, I have to look into my own head and heart and stop warring on others with my thoughts. War is simply a reflection of what we're experiencing on the inside.
From a T-shirt seen on the streets of Geneva: More candy. Less war.
May everything I do be for the greatest good of all!