Schleitheim Confession
The Anabaptist movement in the early sixteenth century taught a combination of moralism and mysticism. Almost without exception, the Anabaptists from Hans Denck (1500–1527), to probably the most learned of all the radicals, Balthasar Hubmaier (1481–1528), to the most moderate of them all, Menno Simons (1496–1561), rejected the Lutheran and Reformed confessional doctrine of justification, for the same reasons that Rome rejected it, because they thought it would tend to encourage immorality and impiety.227 Instead, they sought to promote piety primarily through small groups (conventicles), through private devotional exercises and a strong dose of mysticism. The Schleitheim Confession (1527), in which there was no mention of justification sola gratia, sola fide, solo Christo but strong emphasis on piety and morality is illustrative of this tendency.
Scott Clark, Recovering the Reformed Confession: Our Theology, Piety, and Practice (Phillipsburg, NJ: P&R Publishing Company, 2008)