Kenneth L. Gentry Jr. is an ordained minister in the Presbyterian Church in America. He is the author of several books on Revelation and lives in South Carolina.

The Rev. David Keck is a Presbyterian minister who teaches pastoral education at Duke University. He is the author of Forgetting Whose We Are: Alzheimer’s Disease and the Love of God. He is also pastor at Northgate Presbyterian Church in Durham, N.C.

The Rev. Preston N. Williams is Houghton Research Professor of Theology and Contemporary Change Emeritus at Harvard University, Boston. He directs the Summer Leadership Institute and is an ordained minister in the United Presbyterian Church.

The Pew Forum on Religion and Public Life provides provides a resources page listing religious groups’ official positions on same-sex marriage.

Melanie Hardison works with the Enough for Everyone Project and serves at the national level for the Presbyterian Church.

The Rev. G. Lloyd Rediger of Albuquerque, N.M., is an author, speaker and trainer and is ordained in the Presbyterian Church (U.S.A.). His books include Coping With Clergy Burnout and Clergy Killers: Guidance for Pastors and Congregations Under Attack.

The Presbyterian Peace Fellowship started in the 1940s as a group that provided support to conscientious objectors to World War II and continue to speak out against war. Rick Ufford-Chase is the executive director.

Craig Strickland is senior pastor of Hope Presbyterian Church in Cordova, Tenn., which bills itself as a “church for the unchurched” and relies on social networking sites such as Facebook and Twitter to provide a sense of community.

Read a column by Henry G. Brinton, pastor of Fairfax Presbyterian Church in Virginia, about social networking’s effect on religion. The column appeared June 20, 2010, in USA Today.