Apostasy is to abandon, denounce, reject, or fall away from one’s faith.
Various translations of the Bible uses others words, which also mean apostasy, such as faithfulness, waywardness, rebellion, and turning away.
A person who commits apostasy is called an apostate.
Key verse about apostasy: “Let no one in any way deceive or entrap you, for that day will not come unless the apostasy comes first [that is, the great rebellion, the abandonment of the faith by professed Christians], and the man of lawlessness is revealed, the son of destruction [the Antichrist, the one who is destined to be destroyed]: (2 Thessalonians 2:3, AMP).
A lifelong student of the Bible, Peter DeHaan, PhD, wrote the 700-page website ABibleADay.com to encourage people to explore the Bible. His main blog and numerous books urge Christians to push past the status quo and reconsider how they practice their faith in every area of their lives.