From a Christmas sermon by Martin Luther (Works, 52:20):
Without the gospel there is nothing but desert on earth and no confession of God and no thanksgiving. But where the gospel and Christ are, there is Bethlehem abounding in grain, and grateful Judea; there everybody has enough in Christ and there is nothing but thanksgiving for God’s mercies. But the doctrines of men [ie legalistic attempts at justification with God through pious duty] thank only themselves, and yet they permit arid land and deadly hunger to remain. No heart is ever satisfied unless it hears Christ preached properly in the gospel; when this happens, a person comes to Bethlehem and finds him; then he also comes and stays in Judea and thanks his God eternally; then he is satisfied; then, too, God is praised and confessed. Apart from the gospel there is nothing but ingratitude and we do nothing but die of hunger.