Expiation [ek’-spee-ay‘-shun] (Latin ex- as an intensive prefix + Latin piare, “to atone”) Meaning “to atone, or make reparations for.” In Christian theology the term refers to the penal substitution of Christ on behalf of his people. Specifically it emphasizes the removal of guilt through the payment for the penalty of sin. This notion is coupled with the concept of propitiation, which refers to the appeasement or averting of God’s wrath and justice. Both concepts are seen together as two sides of the same coin.