Rev. Dr. Mark Achtemeier Mark Achtemeier is a minister, author and theologian of the Presbyterian Church (USA).

Mark Achtemeier has served the Presbyterian Church (USA) since 1984 as a minister, speaker, author and theology professor. He taught Theology and Ethics at the University of Dubuque Theological Seminary for fifteen years, and is currently engaged in full-time writing and speaking. He is author of "The Bible's Yes to Same-Sex Marriage: An Evangelical's Change of Heart."