In 1973, 40 evangelical leaders gathered at a YMCA in Chicago to call for a movement against poverty, racism, sexism and violence. Their declaration was drafted by a young urban ministry activist, Jim Wallis, and signed by such evangelical pillars as theologian Carl Henry, a close ally of Billy Graham.

Time Magazine and the Washington Post described it as the social awakening of evangelical America. But a few years later, the Rev. Jerry Falwell’s conservative lobby, the Moral Majority, had taken over as the political voice of evangelicals.

“We certainly didn’t have Jerry in mind when we called for evangelicals to become more socially engaged,” said Ronald Sider, president of Evangelicals for Social Action, which grew out of that 1973 Chicago Declaration.

Now his wing of evangelicalism is emerging from 30 years in the political wilderness. Mr. Wallis is writing bestsellers, and prominent evangelical pastors are calling for “creation care” on global warming and galvanizing church members to address Third World poverty and disease.