The seven deadly sins began as eight, and the Bible lists none of them
You won't find the seven deadly sins listed anywhere in the Bible. They grew out of early monastic thinking, starting with a fourth-century monk's catalogue of eight temptations. Pope Gregory I merged some, added envy and produced the familiar seven in AD 590.
Tertullian first grouped serious sins together, but the decisive step came from Evagrius Ponticus, a fourth-century monk who trimmed a list of nine logismoi, or tempting thoughts, down to eight. They included sadness at another's good fortune and acedia, a listless indifference that especially afflicted monks. His student John Cassian carried the list into the Latin West.
Gregory's revision in 590 folded sadness into acedia, combined vainglory with pride, and brought in envy. Thomas Aquinas defended the list in his Summa Theologica, calling them capital sins because they head and shape all others. Gregory ranked them by growing severity, and lust sat at the mild end: Aquinas reasoned that sins of the flesh, which misuse a faculty shared with animals, weigh less than spiritual ones. Anglican, Lutheran and Methodist churches still teach the list.
Several sins have shifted meaning over the centuries. Gluttony comes from a Latin word meaning to gulp down, and one reason for condemning it was that the rich gorging themselves could leave the poor hungry; Aquinas even counted obsessive anticipation of meals as a form. Gregory defined greed through a string of vices including fraud, perjury and hardness of heart, whereas today it usually means wanting more wealth than one needs.
Sloth has changed most of all. Originally it meant neglecting spiritual duties, and Aquinas described it as sorrow about spiritual good. It later broadened to cover mental apathy and physical idleness. Theologians noted that it differs from the other six because it is a sin of avoiding responsibility rather than committing wrongs. The concept has since inspired painting, church sculpture, literature, film and television.
Source: Seven deadly sins
