MY MOTHER was fond of telling stories, and spinning out their morals. One of her favourites was what, as a child, I knew as "A-boobin' Adam."

In Leigh Hunt's original, Abou Ben Adhem saw an angel writing "the names of those who love the Lord", and discovered that his name was not on the list. "I pray thee, then," Ben Adhem said to the angel, "Write me as one that loves his fellow men." The next day, when the angel came back and showed the names of those whom God had blest, lo! Ben Adhem's name led all the rest.

Real religion, my mother said, was loving your fellow men - not mumbo-jumbo. Of course, the mumbo-jumbo was good for people who did not know any better, but no educated person would believe such things. Real religion was ethics.

In those days, Americans embraced Ben Adhemism from President "Ike" Eisenhower, who famously said that the United States "made no sense" unless founded on a "deeply felt religious faith", but did not care what it meant to the majority of citizens who stoutly maintained that it did not matter what you believed as long as you lived right.

Religious liberals were especially fond of the Ben Adhem doctrine. Dogma was divisive: ethics was ecumenical - it was something on which members of all the great world religions agreed.

But, by the late 20th century, popular culture had absorbed Marx and Freud. It became a commonplace that the moral programme of the great world religions - in particular, Christianity - was oppressive and damaging, and a source of human misery.

Disagreement about what it was to "live right" became more divisive than any dispute about theology. New alliances were formed. Evangelical Protestants collaborated with conservative Roman Catholics, polytheistic Mormons, and other sectarian groups to promote a socially conservative agenda. What mattered was not theology, but sexual conduct, gender roles, and "family values".

Conservative churches, defending an increasingly countercultural moral agenda, captured a niche market: beleaguered social conservatives. In the new millennium, pre-marital sex was a non-issue; a small but growing majority supported gay marriage; and it was taken for granted that women should work outside the home. Only the conservative churches backed socially conservative Americans who were fighting a last-ditch battle against modernity.

Meanwhile, mainline churches - Episcopal, Methodist, Presbyterian, and the like - did not have much to do. The larger society endorsed their ethical programme, and operated numerous organisations to promote it: secular charities; secular civil-rights organisations; and political-action groups that promoted environmentalism, peace, and every other worthy cause.

Liberal churches added more advocacy projects for racial minorities, gays, and other disadvantaged groups, most of whom were perfectly capable of advocating for themselves; and added more charities to the endless list of charities devoted to ameliorating every human ill.

This should have been a cause for celebration. The world, exhorted by liberal pundits, had taken up the Christian ethic of compassion and fairness. At last, the Church could get ethics off its back, and concentrate on religion - fancy buildings and ceremonies, music and mysticism.

But, instead of thanking God that good works and social justice had been taken over by the state and secular charities, mainline churches continued their Ben Adhemist programme, adamant that real religion was simply ethics.

It was hardly surprising that there were few takers for what they offered: if you wanted to do good, then why bother with church; and if you wanted religion, most mainline churches had little to offer.

Dr Harriet Baber is Professor of Philosophy at the University of San Diego, USA.