An intolerable dilemma

Jaques Ellul, writing in 1945 on "collective sin" and the Christian's place in a lost world:

It is now impossible to be isolated, to be separate.  The illusion of a Christian life attached to a convent or hermitage has vanished.  Whether it be due to the simple material fact of communications, or to the interdependence of economic institutions, or to the growth of democracy, in every way these influences combine to force man into this solidarity with others.  Thus the Christian cannot consider himself pure, as compared with others.  He cannot declare that he is free from the sin of the world.  A major fact of our present civilization is that more and more sin becomes collective, and the individual is forced to participate in collective sin. 

[...]

This situation is, however, disagreeable for a Christian...Some will try to dissociate the spiritual situation from the material one, despising the material situation, denying that it has any meaning, declaring that it is neutral, and does not concern eternal life, and that we can turn our attention solely to "spiritual problems."  Such people argue that nothing matters but "the interior life": that is, that to be the "salt" or the "light" is a purely spiritual affirmation, which has no practical consequences.  This is exactly what Jesus Christ calls hypocrisy.  It means giving up any attempts to live out one's religion in the world.  It turns the living person of Jesus Christ into an abstraction.  God became incarnate--it is not for us to undo his work.  This dissociation of our life into two spheres--the one "spiritual," where we can be "perfect," and the other material and unimportant, where we behave like other people--is one of the reasons why churches have so little influence on the world.  This avoidance of responsibility for our faith is evidently a convenient solution for the intolerable dilemma in which we are placed by the society of our day.  All we can say is: this is the exact opposite of what Jesus Christ wills for us, and of that which he came to do. 
 

-Jaques Ellul, The Presence of the Kingdom, pp. 6-7. 

Though I would say 1) the hope of remaining pure by separation has always been an illusion, and 2) this separation of spiritual and material has been an issue for much of the history of the church, Ellul's point nonetheless stands (and is, in fact, made more relevant).