Matthew 18:15—"If your brother sins against you, go and tell him his fault..."—has shaped how churches correct and exclude their members for nearly two millennia. This episode digs into the historical backdrop that made that verse a locus of ecclesiastical power: Jewish practice, the early Fathers, medieval canon law, and Reformation formulations from Calvin to the Polish Brethren. We trace how orthodox teachers read Matthew 18 as a warrant for binding and loosing, penance, and sometimes coercive discipline — and set the stage for the radical re-reading offered by Fausto Sozzini and the Socinians. Expect careful primary-source attention and vivid historical detail as we prepare to enter the Socinian interpretive method.