John Eck's allegation that those advancing justification by faith alone were themselves finding it necessary to distinguish different types of faith describes accurately the reality in the evangelical movement in the 1530s–1550s. The Reformers' initial clarity and optimism about saving faith is seen, for example, in Article 20 of the Augsburg Confession (1530), which describes the scriptural view of faith as a confidence in God and a certain assurance of God's grace. Moreover, the Confession carefully distinguishes this true faith from both mere knowledge of historical events concerning Christ and from virtuous actions that spring from faith, and does not deign to designate these latter legitimate types of faith. However, subsequent dissension within the Protestant camp over the Law (Johann Agricola, for example), justification (Andreas Osiander, for example), and the sacraments, combined with the continued criticism of those Catholic opponents designated by Eck as “the faithful,” forced the magisterial Reformers to defend and, in some cases, refine their understandings of faith. Missing from Eck's assessment, however, is an indication of how exegetical activity in addition to polemical exchanges might attest and even contribute to this reevaluation. In this regard, the Gospel of John constitutes an especially important area for investigation. Protestant understandings of faith were drawn from and bolstered by Pauline texts, especially Rom. 1:17, 3:28, 4:3–9, and 10:17; Gal. 4:6; and Heb.