...it is made clear that action for justice and peace can never mean total commitment to a particular project identified unambiguously as God's will. The concept of missio Dei has sometimes been interpreted so as to suggest that action for justice and peace as the possibilities are discerned within a given historical situation is the fulfillment of God's mission, and that the questions of baptism and church membership are marginal or irrelevant. That way leads very quickly to disillusion and often to cynical despair. No human project however splendid is free from the corrupting power of sin. To invest one's ultimate commitment in such proximate goals is to end in despair.
history of English Christianity in the present century has reminded us that for the first two decades of this period the Christianity of the English Free Churches was interpreted as almost necessarily involving support for the Liberal Party. When the Liberal Party destroyed itself, the Free Churches suffered a blow, a loss of identity, from which they have hardly begun to recover.
It does not require much knowledge of history to recognize that, with all its grievous sins of compromise, cowardice, and apostasy, the Church outlasts all these movements in which so much passionate faith has been invested. In their time each of these movements seems to provide a sense of direction, a credible goal for the human project. The slogans of these movements become sacred words which glow with ultimate authority. But they do not endure. None of them in fact embodies the true end, the real goal of history. That has been embodied once for all in the events which form the substance of the gospel and which-remembered, rehearsed, and reenacted in teaching and liturgy-form the inner core of the Church's being. To commend this gospel to all people in all circumstances, to witness to it as the ultimate clue to the whole human story and therefore to every human story, can never be unnecessary and never irrelevant, however much it may be misunderstood, ignored, or condemned.
Lesslie Newbigin. The Gospel in a Pluralist Society, page 138