The key to the obedience of God's people is not their effectiveness but their patience. The triumph of the right is assured not by the might that comes to the aid of the right, which is of course the justification of the use of violence and other kinds of power in every human conflict. The triumph of the right, although it is assured, is sure because of the power of the resurrection and not because of any calculation of causes and effects, nor because of the inherently greater strength of the good guys. The relationship between the obedience of God's people and the triumph of God's cause is not a relationship of cause and effect but one of cross and resurrection.
This is vintage Yoder; a paragraph that sums up his work as good as any other.
I just spent a week at a junior teens camp, during which I gave three what might be loosely called "theological talks". Afterwards I would ask myself questions like "Did that have any effect?" and "Did I just make up some new words?" and "Their eyes were closed because they were in deep thought, right?"
But if Yoder is right, then I am asking the wrong questions. If I was obedient to the task that was given me, if I was faithful to the gospel, then efficacy is irrelevant. I must only be patient.