The Protestant princes sign a document prepared by Luther's protege Philip Melanchthon, known as the Confession of Augsburg. It lays out the articles of faith of the Lutheran believers, including a doctrinal attachment to the idea of salvation by faith rather than works, which are redefined as the result rather than the cause of holiness. In the face of this document, hopes of an agreement with followers of Ulrich Zwingli diminish, since the Confession of Augsburg declares a belief in the doctrine of the Real Presence at the Eucharist.