Luther accepted Augustine’s view of the church as a mixed body.
The Donatist controversy in the early church provides a lens for understanding how Rome viewed Luther at the outset of the Reformation. This schism arose in North Africa and was a struggle over the nature of the church; or rather, who makes up the church. This became especially acute during times of persecution under the Emperor Diocletian (AD 284-313), under whose reign numerous Christians recanted the faith in the face of torture and execution. Could these Christians repent and rejoin the church in faith once more? What if such a person was a pastor or bishop?
Luther accepted Augustine’s view of the church as a mixed body.
A church leader by the name of Donatus answered no and broke away from the church catholic, because he felt that the church had become corrupt by accepting lapsed believers back into her wings. Cyprian, the bishop of Carthage, was appealed to from both sides of the argument. Cyprian taught there is no salvation outside of the church, but also denounced all forms of schism, leaving the church bereft of a real solution. A stalemate resulted until Augustine arrived and became Bishop of Hippo in the region.
While recognizing the sinfulness of all humanity, Augustine argued that the church was a “mixed body” (corpus permixtum) of saints and sinners based upon his understanding of the parable of the talents (Matt 13:24-30). For Augustine, the church is sanctified and made holy by Christ—a holiness which will be perfected and finally realized at the last judgment. Here we see that sin is an inevitable aspect in the life of the church as it’s made up of redeemed sinner/saints. The Donatist movement ultimately failed to grasp the doctrine of original sin.
From this quick summary of the controversy, it is easy to see how the Church of Rome could look upon the reformers as a break away sect, causing schism much like Donatus in the fourth century, since Luther was also concerned about corruption in the church. Luther accepted Augustine’s view of the church as a mixed body. While condemning the Church of Rome, he never spoke as if there were not believers in her midst, which is unlike the radical reformers whose thought was actually more akin to Donatus. Luther writes:
“We on our part confess that there is much that is Christian and good under the papacy; indeed, everything that is Christian and is good is to be found there and has come to us from this source” (Cited by McGrath, Reformation Thought, 192).
While the papacy may have condemned Luther and his followers as a break away sect, Luther knew he was merely advocating doctrinal reforms within the one true church and in keeping within an Augustinian ecclesiological framework. His desire was not to divide or create a new church, but to reform the corruption that had crept into the one, holy, catholic and apostolic body of Christ. At the same time, however, you find within Luther the importance of maintaining a robust doctrine of the church. For example, Luther sounds reminiscent of Cyprian in this sermon excerpt:
The church is not wood and stone but the assembly of people who believe in Christ. With this church, one should be connected and see how the people believe, live, and teach. They certainly have Christ in their midst, for outside the Christian church there is no truth, no Christ, no salvation. (LW 52, 40).
By holding to such an understanding of the church, Luther found himself caught between the extremes of Rome on one side and the fanatics on the other, which is just one reason the Lutheran Reformation can rightfully be called the “Conservative Reformation.”