The non-violent resistor not only avoids external, physical violence, but he avoids internal violence of spirit. He not only refuses to shoot his opponent, but he refuses to hate him. And he stands with understanding, goodwill at all times.
If your opponent has a conscience, then follow Gandhi and nonviolence. But if your enemy has no conscience like Hitler, then follow Bonhoeffer.
It is better to be the recipient of violence than the inflicter of it, since the latter only multiplies the existence of violence and bitterness in the universe, while the former may develop a sense of shame in the opponent, and thereby bring about a transformation and change of heart.