What group is more qualified than the Catholic bishops to raise ethical questions about the defects of the American economy? No other private organization in the country has done more, or risked more, on behalf of the victims of those cruel and ingrained defects.

In every one of the church's 180 diocese, it is the bishop who has final responsibility for raising the money and paying the bills for the protean services that are the works of mercy and rescue. In thousands of Catholic- run orphanages, old-age homes, schools, hospitals, soup kitchens, homeless shelters and peace centers, the services are delivered in rosy times and hard.

Out of this have come the saints -- Mother Cabrini, Elizabeth Seton; the scholars -- Paul Hanley Furfey of Catholic University, Theodore Hesburgh of Notre Dame; the prophets -- Daniel Berrigan, Dorothy Day and John Shiel; the street-wise organizers -- Geno Baroni, Charles Owen Rice. The American-based Catholic Relief Services is the world's largest private foreign-aid program.

The church's sacramental life has always been twinned with its humanitarianism. Because of that, the bishops' thoughts on the flawed American economy would deserve a hearing anytime. The urgency of the present moment is that with much of the nation backing policies that help generate more poverty at home and more destitution abroad, moral voices in opposition are needed as much as political ones. Every parish priest in the nation has stories of frightened families coming to the rectory door as a last-hope shot for food, clothes or perhaps a loan for the fuel bill. In the past few years, the doorbells have been ringing unceasingly as the Reagan administration tells the churches and other private groups: you feed the poor and we'll feed the military.

The bishops are not speaking out of turn or out of context. They are in alignment with Pope John Paul II, a global man as aware as anyone that half the world's people live in countries with per-capita incomes of $400 or less while in the United States it is $12,530.

Two months ago in Alberta, Canada, the pope spoke of the "poor South and the rich North." Is it possible that he didn't have the United States in mind with this searing statement: "The poor people and poor nations -- poor in different ways, not only lacking food, but also deprived of freedom and other human rights -- will judge those people who take these goods away from them, assuming to themselves the imperialistic monopoly of economic and political supremacy at the expense of others."

It is jarring to be told that despite our seeming generosity as a nation and our commitment to democracy, we are in "the imperialistic monopoly." The phrase sounds like a title for a Pravda editorial. For many defenders of the monopoly, the bishops are now being ridiculed as do-gooders taken in by the "the liberal agenda."

What do bishops, scorners ask, know about reforming tax structures, Third World debt, welfare policies and military extravagance -- all topics in the draft letter? They know a lot. A church that for 20 centuries has sided with the poor surely has learned something about solutions to economic problems that Caesar and his friends won't face.

The hierarchy's tone, too, is not as pious as the critics would like: "Some go on perpetuating the myth," the bishops write in frankness, "that the country is being bankrupted by welfare programs, when in fact the total costs of programs for the poor come to less than 10 percent of the federal budget."

The idea for a moral examination of the American economy originated with Bishop Peter Rosazza of Hartford. Four years ago when his brothers issued a statement on Marxism, he asked with logic: why don't we now look at our own system?

The looking has been small "c" Catholic. In four years, with more than 110 people offering their views before the five-bishop committee, the range has been wide: the chief economist of General Motors, the chairman of Lehman Brothers, farm workers, socialists, the director of Catholic Charities, a black single working parent.

The final draft of this pastoral letter is due next November. Improvements are needed. Latin America's bishops have been much more blunt in condemning those who reduce religion to matters of personal morality but exclude it from impersonal economic decisions that may kill or injure people.

Another weakness is in ignoring the impoverishing effects of expanding population. "The international economic order is in crisis," say the bishops, but they refuse to see, once again, that the crisis won't be eased until Catholic leaders begin to support population control programs.

Between now and next year, some radicalizing is in order. An unradical Christianity is a contradiction. If faith can move mountains, it can move capitalism.