MLK on the church: "thermometer" or "thermostat"?

There was a time when the church was very powerful -- in the time when the early Christians rejoiced at being deemed worthy to suffer for what they believed. In those days the church was not merely a thermometer that recorded the ideas and principles of popular opinion; it was a thermostat that transformed the mores of society. Whenever the early Christians entered a town, the people in power became disturbed and immediately sought to convict the Christians for being "disturbers of the peace" and "outside agitators." But the Christians pressed on, in the conviction that they were "a colony of heaven," called to obey God rather than man. Small in number, they were big in commitment. They were too God-intoxicated to be "astronomically intimidated." By their effort and example they brought an end to such ancient evils as infanticide and gladiatorial contests. Things are different now. So often the contemporary church is a weak, ineffectual voice with an uncertain sound. So often it is an archdefender of the status quo. Far from being disturbed by the presence of the church, the power structure of the average community is consoled by the church's silent -- and often even vocal -- sanction of things as they are.

But the judgment of God is upon the church as never before. If today's church does not recapture the sacrificial spirit of the early church, it will lose its authenticity, forfeit the loyalty of millions, and be dismissed as an irrelevant social club with no meaning for the twentieth century. . .

Martin Luther King, Jr., Letter from a Birmingham Jail