Eschatology ⁱ/ˌɛskəˈtɒlədʒi/ (from the Greek ἔσχατος/ἐσχάτη/ἔσχατον, eschatos/eschatē/eschaton meaning "last" and -logy meaning "the study of", first used in English around 1550) is a part of theology, philosophy, and futurology concerned with what are believed to be the final events of history, the ultimate destiny of humanity—commonly referred to as the end of the world or the "World to Come."

The Oxford English Dictionary defines eschatology as "The department of theological science concerned with ‘the four last things: death, judgement, heaven, and hell’."

In the context of mysticism, the phrase refers metaphorically to the end of ordinary reality and reunion with the Divine. In many religions it is taught as an existing future event prophesied in sacred texts or folklore. More broadly, eschatology may encompass related concepts such as the Messiah or Messianic Age, the end time, and the end of days.

Steven Garrett "Steve" Gregg (born 3 November 1955 in Wilmington, Delaware) is a former American swimmer. He represented the United States at the 1976 Summer Olympics in Montreal, where he won a silver medal in the 200-meter butterfly, finishing behind compatriot Mike Bruner. Not to be confused with partial Preterist Steve Gregg (born 29 May 1953).

Gary DeMar is an American writer, lecturer and the president of American Vision, an American Christian nonprofit organization. The think-tank has a vision of "an America that recognizes the sovereignty of God over all of life and where Christians are engaged in every facet of society".

DeMar resides in Marietta, Georgia with his wife Carol. They have two grown sons. DeMar is a member of Midway Presbyterian Church, affiliated with the Presbyterian Church in America. DeMar graduated from Western Michigan University in 1973 and earned a M.Div. from Reformed Theological Seminary in 1979. He earned his Ph.D. in Christian Intellectual History from unaccredited, online Whitefield Theological Seminary in 2007.

DeMar began working at American Vision in 1981 as a research analyst. In 1986 he became the president of the organization. DeMar is the author of 25 books. Beginning on June 3, 2006, DeMar began hosting "The Gary DeMar Show", a radio program airing live from Atlanta, every Saturday at noon ET." The Gary DeMar Show" now is available as a podcast every weekday for 10 minutes and as a video-cast on YouTube.