Timothy Longman is director of the African Studies Centre at Boston University and author of Commanded by the Devil: Christianity and Genocide in Rwanda (Cambridge University Press).

Richard J. Foster, who lives in the Denver area, is the author of Freedom of Simplicity: Finding Harmony in a Complex World (HarperSanFrancisco, 25th anniversary edition, 2005). He is a Quaker and the founder of Renovaré, a movement committed to church renewal.

Congregation Or Atid, a Conservative synagogue in Richmond, Va. conducts a “Switch Day,” when members take the shifts of Christian volunteers at nearby Beth Sholom Nursing Home.

Since 1990, Cedar Village, a retirement and nursing home in Mason, Ohio, has held a “Mitzvah Day” every Dec. 25, in which Jewish staff members volunteer to work for Christian staffers. Contact Rachel Festenstein, director of marketing and community outreach.

Read a Christianity Today article, “Peace on Earth? Christmas Carols and the Civil War.”

Read a pair of December 2003 columns by Terry Mattingly about carols: “A Caroling We (Don’t) Go” and “What is a ‘carol’ anyway?”

Kenneth W. Osbeck of Rockford, Mich., is the author of Amazing Grace: 366 Inspiring Hymn Stories for Daily Devotions (Kregel Publications, 2002) and Joy to the World: The Stories Behind Your Favorite Christmas Carols (Kregel, 2000).

Christmas music historian Ron Clancy of North Cape May, N.J., produces the “Millennia Collection,” a multivolume set of Christmas music books and CDs.

The painting “Christ the Yogi” hangs at the San Francisco temple of the Vedanta Society of Northern California, where congregants regard Jesus to be a spiritual master who embodied pure love.