The acting president of Haverford College in Pennsylvania, whose scholarly interests range from Marxism to Jewish-Christian interaction, will become dean of Harvard's Divinity School July 1.

The Rev. Ronald F. Thiemann, 39, will be the fourth dean to head the Divinity School--Harvard's oldest graduate school--in less than a year. George E. Rupp left this summer after six years to become president of Rice University in Houston. Rupp's successor as acting dean, George W. Macrae, died this fall. John B. Carman was named acting dean after Macrae, and will continue until Thiemann arrives.

"Macrae's untimely death shook the school," Bussey Professor of Divinity Paul D. Hanson said yesterday. "Anticipation of [Thiemann's] arrival has energized the faculty."

Thiemann faces a host of challenges to tackle. The school, with about 30 faculty members, is looking for five scholars to fill three endowed chairs and two assistant professorships.

The Divinity School, with a $30 million endowment and 80 percent of its students on financial aid, is also the poorest of Harvard's schools. Thiemann will have to pick up fundraising where his predecessor Rupp left off, according to John Strugnell, Lamont Professor of Divinity.

"Rupp was effective but he didn't finish the job of refunding the whole school," said Strugnell. "We all agree we need more money."

In addition to finding top-notch professors, Thiemann will work to attract good students and maintain the last few years' upsurge in applicants, said Dean of Students Guy V. Martin. The student body has grown 20 percent over the last five years to 450, and applications have jumped 15 percent over the last year, according to Martin.

Thiemann, an ordained Lutheran minister, comes to Harvard after 10 years of teaching and administration at Haverford, a Quaker School. He received his B.A. from Concordia Senior College in Indiana and three graduate degrees from Yale. He was not available for comment yesterday.

"He has proven in administrative work and teaching at Haverford a style of leadership which enables people to cooperate without sacrificing particular aspects of their theological tradition," said Hanson.

Hanson described Thiemann as "energetic and industrious" and "an administrative expert.