In time of war in an occupied country, a member of the resistance meets one night a stranger who deeply impresses him. They spend that night together in conversation. The Stranger tells the partisan that he himself is on the side of the resistance – indeed that he is in command of it, and urges the partisan to have faith in him no matter what happens. The partisan is utterly convinced at that meeting of the Stranger’s sincerity and constancy and undertakes to trust him.
They never meet in conditions of intimacy again. But sometimes the Stranger is seen helping members of the resistance, and the partisan is grateful and says to his friends, ‘He is on our side.’ Sometimes he is seen in the uniform of the police handing over patriots to the occupying power. On these occasions his friends murmur against him; but the partisan still says, ‘He is on our side.’ He still believes that, in spite of appearances, the Stranger did not deceive him. Sometimes he asks the Stranger for help and receives it. He is then thankful. Sometimes he asks and does not receive it. Then he says, The Stranger knows best.’
Sometimes his friends, in exasperation, say, ‘Well, what would he have to do for you to admit that you were wrong and that he is not on our side?’ But the partisan refuses to answer. He will not consent to put the Stranger to the test. And sometimes his friends complain, ‘Well, if that’s what you mean by his being on our side, the sooner he goes over to the other side the better.’
Basil Mitchell
You can read more analysis of this in its original context here.