Tim Warner is pastor of Oasis Christian Church in Tampa, Fla., and author of the website Answers in Revelation.

Thomas B. Slater is a professor of New Testament at Mercer University’s McAfee School of Theology in Atlanta. He has said that Family Radio’s billboards claiming that Jesus would return on May 21, 2011, were inherently misguided.

Dick J. Reavis is an associate professor of English at North Carolina State University. He studied the history of end-times movements while researching his book about the Branch Davidians,  The Ashes of Waco: An Investigation.

The Rev. Jonathan Marlowe is co-pastor of Gibsonville United Methodist Church in Gibsonville, N.C. He preached a four-week sermon series on the Book of Revelation and blogged about it.

Kevin Lewis is a professor of religious studies at the University of South Carolina in Columbia. He teaches a course called “Visions of Apocalypse” and has written an essay on Americans’ obsession with the apocalypse.

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.

Rebecca Denova is a lecturer in religious studies at the University of Pittsburgh in Pittsburgh, Pa., where she has taught a course called “Apocalypse Then and Now.”

Anthony Aveni is the Russell Colgate Distinguished University Professor of Astronomy and Anthropology and Native American Studies at Colgate University in Hamilton, N.Y., and author of The End of Time: The Maya Mystery of 2012.

Bishop Terry Wiles is leader of Crossroads Community Cathedral in East Hartford, Conn. The church lists a literal belief in the Rapture as central to its members’ faith and membership.