When an unknown monk posted a placard of theological points on a church door, he did not know that he would cause a spiritual revolution that would still affect us hundreds of years later. But at the heart of the Reformation lay Martin Luther's great discovery, and a challenge that is still needed today: Repentance is not the action of a single moment, but a characteristic of a Christian's entire life.

Sinclair Ferguson looks at the biblical definition of repentance, how some modern churches are repeating medieval errors, and the necessity of reformation. Whereas current teaching often belittles repentance, Ferguson believes that not only is it essential for salvation, it is the concrete expression of divine regeneration. When we see what we truly are--innately, inescapably sinful--we know our deep need for God's abundant grace. To this Ferguson declares, "According to Scripture, the Christian life is repentance from beginning to end! So long as the believer is at the same time righteous and yet a sinner, it can be no other way."