On the Babylonian Captivity of the Church

Prelude on the Babylonian Captivity of the Church (October 1520) was the second of the three major treatises published by Martin Luther in 1520, coming after the Address to the Christian Nobility of the German Nation (August 1520) and before On the Freedom of a Christian (November 1520). It was a theological treatise, and as such was published in Latin as well as German, the language in which the treatises were written.

In this work Luther examines the seven sacraments of the Catholic Church in the light of his interpretation of the Bible. With regard to the Eucharist, he advocates restoring the cup to the laity, dismisses the Catholic doctrine of Transubstantiation but affirms the real presence of the body and blood of Christ in the Eucharist, and rejects the teaching that the Mass is a sacrifice offered to God.

With regard to baptism, he writes that it brings justification only if conjoined with saving faith in the recipient; however, it remains the foundation of salvation even for those who might later fall and be reclaimed.

As for penance, its essence consists in the words of promise (absolution) received by faith. Only these three can be regarded as sacraments because of their divine institution and the divine promises of salvation connected with them; but strictly speaking, only Baptism and the Eucharist are sacraments, since only they have "divinely instituted visible sign[s]": water in Baptism and bread and wine in the Eucharist. Luther claimed that Confirmation, Matrimony, Holy Orders, and Extreme Unction are not sacraments.

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