Men must continue to condemn themselves not only for their failure to do what they could, but also for their failure to perform what they could not, … - H. Richard Niebuhr

The movement of withdrawal and renunciation is a necessary element in every Christian life. ... It is an inevitable answer; but it is also inadequate. ... It is inadequate, for one thing, because it affirms in words what it denies in action; namely, the possibility of sole dependence on Jesus Christ to the exclusion of culture. Christ claims no man purely as a natural being, but always as one who has become human in a culture; who is not only in culture, but into whom culture has penetrated.

Radical Christians are always making use of the culture, or parts of the culture, which they ostensibly reject.

The difference between the radicals and the other groups is often only this: that the radicals fail to recognize what they are doing, and continue to speak as though they were separated from the world.