We live in a world of epidemic violence. And since the experience of humankind is that violence begets greater violence, which then begets even greater violence, we must resolve to eschew all violence. Can we make such witness without pain or sacrifice as regards ourselves or others? No, certainly not!
The situation in the world has become so bad that only by human self-sacrifice can humankind (and the rest of God's holy creation here on Earth) be saved. If this Earth is to be freed from sin and to be restored to its original state of wholeness, and holiness, then guilty people will go unpunished and innocent people will suffer. It will all be unavoidable!
It is the will of God that we should love one another - and love all of his holy creation. We cannot do this if we visit violence upon one another - and the rest of creation. Especially if that violence is that of armed conflict, of war, which is institutionalised. To be truly obedient unto him, we must, like Jesus, become true pacifists.