In an analysis of the work of Meredith Kline, John Frame offers this neat formulation of the relation of faith, works, and reward:

“Today we receive salvation by faith alone, apart from works. But that faith must be a living, working faith, if it is true faith (Jms. 2:14-26). As with Abraham, God rewards our trust, even in the midst of persecution and difficulty (Mark 10:29-30). Those rewards are the beginning of the rewards we finally inherit at the consummation of God’s kingdom.”