Original sin (Latin: peccatum originale) in Christian theology refers to the condition of sinfulness that all humans share, which is inherited from Adam and Eve due to the Fall, involving the loss of original righteousness and the distortion of the Image of God. The biblical basis for the belief is generally found in Genesis 3 (the story of the expulsion of Adam and Eve from the Garden of Eden), and in texts such as Psalm 51:5 ("I was brought forth in iniquity, and in sin did my mother conceive me") and Romans 5:12–21 ("Therefore, just as sin entered the world through one man, and death through sin, and in this way death came to all people, because all sinned").
The specific doctrine of original sin was developed in the 3rd century struggle against Gnosticism by Irenaeus of Lyons, and was shaped significantly by Augustine of Hippo (354–430 AD), who was the first author to use the phrase "original sin". Influenced by Augustine, the Councils of Carthage (411–418 AD) and Orange (529 AD) brought theological speculation about original sin into the official lexicon of the Church.
Protestant Reformers such as Martin Luther...