WASHINGTON — Diane Knippers, an intellectual heavyweight who rallied opposition to the liberal drift of mainline churches and was named by Time magazine as one of the country's 25 most influential evangelicals, died Monday (April 18). She was 53.

Knippers had battled colon cancer for more than a year and was admitted to intensive care at a Virginia hospital as the cancer spread to her lymph nodes.

Knippers was president of the Washington-based Institute for Religion and Democracy (IRD), a conservative think tank whose roots were in protecting Christian minorities overseas but found its footing as a counter voice to liberal mainline Protestant churches.

On April 4, Knippers took a seven-month writing leave from IRD as her condition worsened.

In recent months, she worked with the National Association of Evangelicals as co-editor of "Toward an Evangelical Public Policy," a political manifesto that urged conservative Christians to expand their policy agenda in Washington and beyond.

"She set an example of faithful Christian witness amidst church and political conflicts," said Alan Wisdom, IRD's vice president. "She was firm in her conviction of God's truth, and that firmness enabled her to show a great serenity and warmth toward others."

Raised as the daughter of a United Methodist minister, she emerged as a respected voice within the Episcopal Church in opposition to the ordination of an openly gay bishop in New Hampshire.

Knippers was a key lay leader at Truro (Episcopal) Church in Fairfax, Va., a bulwark of the conservative Episcopal movement, and was a member of the board of directors of the American Anglican Council.

"It's our loss but heaven's gain," said the Rev. Kendall Harmon, a South Carolina Episcopal priest and ally ...