Grace and the 'Protestant work ethic'

"Calvin’s expansive view of God’s sovereignty, combined with the depth of his security in God’s grace, produced an astounding drive to productivity in both himself and those he influenced. Many have called it “the Protestant work ethic.” It may be counterintuitive at first. The natural mind thinks that motivating great exertions of effort requires withholding the reward. Work first for God, then get acceptance from him later.
But the Christian gospel does precisely the opposite. By faith the Christian is connected to Jesus first and foremost, fully accepted by God, before being required to do anything (only to believe, which is itself a divine gift, Eph. 2:8; Phil. 1:29). Amazingly, such radical grace transforms, and thus frees the Christian to exert great intensity and zeal in the cause of gospel good. Such transforming and freeing grace produces a man like Calvin so energized for doing good that as he lay dying in bed for weeks, he continued to dictate substance and letters of encouragement to others until only eight hours before his passing, as his voice finally gave out."

David Mathis: 'Divine Glory and the Daily Grind' in "With Calvin in the Theater (sic) of God", p. 23.