Apostasy ( /əˈpɒstəsi/; Greek: ἀποστασία (apostasia), 'a defection or revolt', from ἀπό, apo, 'away, apart', στάσις, stasis, 'stand, 'standing') is the formal disaffiliation from or abandonment or renunciation of a religion by a person. One who commits apostasy (or who apostatises) is known as an apostate. These terms have a pejorative implication in everyday use. The term apostasy is used by sociologists to mean renunciation and criticism of, or opposition to, a person's former religion, in a technical sense and without pejorative connotation.

The term is sometimes also used metaphorically to refer to renunciation of a non-religious belief or cause, such as a political party, brain trust, or, facetiously, a sports team.

Apostasy is generally not a self-definition^{[citation needed]}: very few former believers call themselves apostates because of the pejorative implications of the term.

Many religious groups and some states punish apostates. Apostates may be shunned by the members of their former religious group or subjected to formal or informal punishment. This may be the official policy of the religious group or may be the action of its members. Certain types of churches may in certain circumstances excommunicate the apostate, while some religious scriptures demand the death penalty for apostates.

Charles "Chuck" Missler is an author, evangelical Christian, Bible teacher, former businessman and US Naval officer. He is the founder of the Koinonia House ministry based in Coeur d'Alene, Idaho.

Missler was for several years the chairman, the chief executive, and the largest shareholder of Western Digital. In 1983 he became the chairman and chief executive of Helionetics Inc., another technology company. After teaching for many years at Calvary Chapel Costa Mesa, Missler moved to Coeur d'Alene in 1992 and founded Koinonia House. Through this organization, Missler distributes a monthly newsletter, Bible study tapes, and a radio show, and speaks at conferences.

Missler is a prominent speaker on the subject of bible prophecy. Missler has had numerous programs aired on the Christian television station GOD TV, namely the DVD versions of his biblical studies "Learn the Bible in 24 Hours", "The Book of Revelation", "The Book of Genesis", and "The Book of Daniel".^{[citation needed]} A Los Angeles Times article reported that Missler and co-author Hal Lindsey had plagiarized a portion of Miami University Professor Edwin Yamauchi's 1982 book Foes From the Northern Frontier in their own 1992 book The Magog Factor. A YouTube video in which Missler uses a jar of peanut butter to attempt to disprove evolution attracted media attention in 2007-2008.

Clinton Richard Dawkins, FRS, FRSL (born 26 March 1941), known as Richard Dawkins, is a British ethologist, evolutionary biologist and author. He is an emeritus fellow of New College, Oxford, and was the University of Oxford's Professor for Public Understanding of Science from 1995 until 2008.

Dawkins came to prominence with his 1976 book The Selfish Gene, which popularised the gene-centered view of evolution and introduced the term meme. In 1982 he introduced an influential concept into evolutionary biology, presented in his book The Extended Phenotype, that the phenotypic effects of a gene are not necessarily limited to an organism's body, but can stretch far into the environment, including the bodies of other organisms.

Dawkins is an atheist, a vice president of the British Humanist Association, and a supporter of the Brights movement. He is well known for his criticism of creationism and intelligent design. In his 1986 book The Blind Watchmaker, he argued against the watchmaker analogy, an argument for the existence of a supernatural creator based upon the complexity of living organisms. Instead, he described evolutionary processes as analogous to a blind watchmaker. He has since written several popular science books, and makes regular television and radio appearances, predominantly discussing these topics. In his 2006 book The God Delusion, Dawkins contends that a supernatural creator almost certainly does not exist and that religious faith is a delusion—"a fixed false belief." As of January 2010 the English-language version has sold more than two million copies and had been translated into 31 languages.