ζύμη

Leaven works quietly and extensively, which makes it a fitting image for tolerated influence. In Corinth, the problem is not private imperfection but public sexual immorality compounded by arrogant inaction. Paul's Passover language places discipline under Christ's sacrifice and calls the church toward sincerity and truth. In Galatia, the permeating danger is teaching that makes circumcision and law-observance necessary for justification, thereby compromising freedom in Christ.

These are serious, identified threats, not permission to label every disagreement “leaven. ” Churches should neither ignore patterns because they seem small nor create fear through vague contagion language. Faithful response names the actual sin or doctrine, follows scriptural processes, seeks repentance and restoration, and remembers that cleansing rests on Christ our Passover.

The image summons corporate responsibility without encouraging gossip, collective punishment, or purity panic.

Ζύμη is the noun for leaven or fermented dough. Its metaphorical meaning is not fixed as evil; the surrounding comparison identifies what permeates and whether that influence is welcomed or condemned. Paul's proverb emphasizes extensive effect from a small amount.