There's a small sign outside Jim Wall's unpretentious downtown office: ''God was here. But he left early.'' It's meant to be amusing - but not irreverent. The Rev. James M. Wall's job is to see that the Deity is ever present in his work. An ordained Methodist minister, Mr. Wall is also editor of one of the nation's most prestigious Protestant publications, The Christian Century. He defines his magazine's role in terms of ''standing at the intersection of faith and society.''
That's just what the Century has been doing for the past century. And, as it celebrates its centennial year, Mr. Wall vows it will continue along this path during the next hundred years. Designed originally to serve a narrow eucumenical community, the Century's bold stances on political and social issues now attract a broader audience. But its positions have also placed it in the center of controversy - even to the point where it once lost its tax exemption for openly endorsing a presidential candidate. (The publication threw caution to the winds in 1964 and favored Lyndon Johnson over Barry Goldwater.)
Mr. Wall insists that there is a ''moral dimension to every political issue ... that affects how people act.'' But he concedes that candidate endorsement is ''improper'' for a religious publication.
What is proper? Articles and editorials on every salient issue ranging from abortion and child abuse to civil rights, women's rights, and nuclear uses.
For instance, as early as 1919 the Century beat the drum for women's suffrage. In the 1920s Charles Clayton Morrison, then editor, was instrumental in shaping the historic Kellogg-Briand Peace Pact, outlawing war. Early in World War II, the publication took an unpopular position against the internment of Japanese-Americans in relocation camps. A decade later, it struck a sharp chord for racial equality by signing on the Rev. Dr. Martin Luther King as a contributing editor.
Of late, the Century has championed an antinuclear stance, challenged the Reagan administration for chipping away at church-state separation, and tackled such ''hot'' issues as abortion and the role of homosexuals in the church.
Many Protestants see the publication as their ''liberal'' editorial spokesman - closely aligned on most issues with the World Council of Churches and its US component, the National Council of Churches (NCC). On the other hand, Christianity Today (a leading magazine for the Protestant ministry, with a circulation of 180,000) purports to speak for evangelicals and conservative ecumenicals.
The Rev. Mr. Wall, however, rejects ideological stereotyping. ''In fact, we are more neo-liberal of late than liberal,'' the editor insists. For instance, he says his magazine generally supports thrusts to preserve the environment but also sees the need for balance between ecology and industry. And on the sensitive subject of the status of homosexuals in the theological community, the Century supports ''involvement'' in church life but defends the right of groups like the NCC to reject membership of an avowed ''gay'' church.
''A church should be able to set its own standards.... There is no inherent 'gay right,' '' says Mr. Wall.
On the nuclear issue, the Century leaves no doubt where it stands. It is firmly against nuclear testing and supports the stances of liberal Protestant and Jewish groups and the US Conference of Catholic Bishops in advocating strict limits up to and including a nuclear freeze. Mr. Wall says the ''nuclear issue is the key moral issue of our time. ... It joins segregation as the moral issue of overwhelming proportions.''
The Century's first hundred years have been ones of constant challenges and struggles for survival. Funds have always been meager, circulation modest, and staffing small. Nevertheless, regularly contributed articles by leading Protestant thinkers, such as Reinhold Niebuhr and Charles Clayton Morrison, injected the Century into worldwide theological discussions. Originally founded in 1884 as the Christian Oracle, the name was changed in 1900 to greet the 20th century.
The Rev. Mr. Wall entered the picture as editor in 1972, when the Century was on the brink of fiscal disaster. A professional writer and teacher, he had served the previous 10 years as editor of the Christian Advocate, an official Methodist publication. The journalist-theologian was also later appointed by Jimmy Carter as a member of the President's Commission on White House Fellows.
With some aggressive fiscal belt-tightening, the Rev. Mr. Wall turned a deficit into a modest profit. The Century still operates on a shoestring - with a $1 million annual budget. It employs only 15 full-time workers to get out 42 issues a year to serve a circulation of 40,000 clergy, scholars, and ''concerned lay people.''
The Century's readers now include Roman Catholic and Jewish leaders. ''They want to know what the Protestant mainline is thinking about,'' Mr. Wall explains.
What of the future? Editor Wall hopes to initiate, among other things, a ''more sophisticated discussion of the economy.''
He also says the magazine will concern itself more with the arts - making ''aesthetic judgments within the context of Christian tradition.''
On the occasion of the magazine's 100th anniversary this year, editor Wall invited church leaders from across the ideological spectrum as well as public figures to assess the Century. He specifically asked for constructive criticism - rather than testimonials. And that's what he got.
Jimmy Carter, a longtime reader and supporter, warned of intellectual snobbery, indicating preoccupation ''with the analysis, debate, and examination of ideas from an ivory tower.''
Evangelical Christian scholar Carl F. H. Henry praised the magazine for gradually emerging from a predictable and unbending liberal view of every issue. And Michael Novak, an outspoken Roman Catholic intellectual, urged the Century to bolster its credibility among nonliberals by using articles by more conservative and neoconservative writers.
Liberal Jewish leader A. James Rudin chided the Protestant publication for its earlier lack of sympathy for Israel. But Rabbi Rudin also praised the Century's ''clear, articulate, and above all, independent voice.''
Does the Christian Century draw the line on discussing any subjects? Seldom. But it does handle some issues - such as homosexuality and abortion - delicately. Any taboos? Mr. Wall sees almost none. He says every political and social issue has religious or moral overtones. ''And the world is our parish,'' he adds.