Apostasy in Christianity is the repudiation of Christ and the central teachings of Christianity by someone who formerly was a Christian (Christ-follower). The term apostasy comes from the Greek word apostasia ("ἀποστασία") meaning "rebellion", "state of apostasy", "abandonment", or "defection". It has been described as "a willful falling away from, or rebellion against, Christianity. Apostasy is the rejection of Christ by one who has been a Christian. …" "Apostasy is a theological category describing those who have voluntarily and consciously abandoned their faith in the God of the covenant, who manifests himself most completely in Jesus Christ." "Apostasy is the antonym of conversion; it is deconversion."
B. J. Oropeza, who has written one of the most exhaustive studies on the phenomenon of apostasy in the New Testament (3 Volumes, 793 pages), "uncovered several factors that result in apostasy." Some of these factors overlap, and some Christian communities were "susceptible to more than one of these." The first major factor in a believer committing apostasy (i.e., becoming an unbeliever) is "unbelief." Other factors potentially leading to apostasy include: "persecution," "general suffering and hardship," "false teachings and factions," "malaise," "indifference and negligence towards the things of God" (specifically, "the command to love one's neighbors"), and engaging in sinful acts ("vice-doing") or assimilating to the ungodly attitudes and actions reflected in a non-Christian culture.
Biblical teaching
For additional biblical teaching on the possibility of apostasy see
The Greek noun apostasia (rebellion, abandonment, state of apostasy, defection) is found only twice in the New Testament (Acts ; 2 Thessalonians ). However, "the concept of apostasy is found throughout Scripture." The related verb aphistēmi (go away, withdraw, depart, fall away) carries considerable theological significance in three passages (Luke 8:13; 1 Timothy 4:1; Hebrews 3:12).
In The New International Dictionary of New Testament Theology, Wolfgang Bauder writes:
1 Timothy 4:1 describes "falling away from the faith" in the last days in terms of falling into false, heretical beliefs. Lk. 8:13 probably refers to apostasy as a result of eschatological temptation. Here are people who have come to believe, who have received the gospel "with joy." But under the pressure of persecution and tribulation arising because of the faith, they break off the relationship with God into which they have entered. According to Hebrews 3:12, apostasy consists in an unbelieving and self-willed movement away from God (in contrast to Hebrews 3:14), which must be prevented at all costs. aphistēmi thus connotes in the passages just mentioned the serious situation of becoming separated from the living God after a previous turning towards him, by falling away from the faith. It is a movement of unbelief and sin, which can also be expressed by other words (cf. the par. to Luke 8:13 in Matthew 13:21; Mark 4:17; …). Expressions equivalent in meaning to the warning in 1 Timothy 4:1 include nauageō, suffer shipwreck, 1:19; astocheō miss the mark, 1:6; 6:21; 2 Timothy 2:18; cf. also aperchomai, go away, John 6:66; apostrephō, turn away; arneomai, deny; metatithēmi, change, alter; mē menein, do not abide, John 15:6; … [see also] the pictures of defection in Matthew 24:9–12, and Revelation 13."
Wolfgang Bauder goes on add that piptō, fall (1 Corinthians 10:12; Hebrews 4:11), and ekpiptō, fall off or from (Galatians 5:4; 2 Peter 3:17), is used figuratively in the New Testament to refer to "the consequent loss of salvation, rather than of a mere failure from which recovery can be made. It is a catastrophic fall, which means eternal ruin. If it were not so, all the warnings against falling would lose their threatening urgency. To fall into sin and guilt, as an expression of a total attitude, is to plunge into irrevocable misfortune."
The following passages where the verb skandalizō ("fall away from faith") and the noun skandalon ("enticement to unbelief, cause of salvation's loss, seduction"): are theologically important as well:
Heinz Giesen, in the Exegetical Dictionary of the New Testament, writes: