Bonhoeffer’s The Cost of Discipleship challenges the way we think about salvation to the core. Is grace really so simple as a wave of the Deistic wand, and–*poof*–sins forgiven, nothing else necessary? 
Grace was meant to do more than justify sin. In fact, it wasn’t meant to justify sin. Sin will never be justified; it will always and forever be offensive to God and contrary to his nature. It was the plan of God, however, to justify sinners–children of God who had fallen into the unescapable mire of depravity. Justification lifts those sinners from the muck, and washes them clean.
According to Bonhoeffer, the justification of sinners is encapsulated in the simple command of Jesus: “Follow me.” Below is his take on what he calls costly grace. (If you didn’t catch Part 1: Cheap Grace, make sure you do. We cannot appreciate the cost of grace before we realize how cheap it really has become to us.):
Costly grace is the treasure hidden in the field; for the sake of it a man will gladly go and sell all that he has. It is the pearl of great price to buy which the merchant will sell all his goods. It is the kingly rule of Christ, for whose sake a man will pluck out the eye which causes him to stumble; it is the call of Jesus Christ at which the disciple leaves his nets and follows him.
Costly grace is the gospel which must be sought again and again, the gift which must be asked for, the door at which a man must knock.
Such grace is costly because it calls us to follow, and it is grace because it calls us to follow Jesus Christ. It is costly because it costs a man his life, and it is grace because it gives a man the only true life. It is costly because it condemns sin, and grace because it justifies the sinner. Above all, it is costly because it cost God the life of his Son: “ye were bought at a price,” and what has cost God much cannot be cheap for us. Above all, it is grace because God did not reckon his Son too dear a price to pay for our life, but delivered him up for us. Costly grace is the Incarnation of God.
Costly grace is the sanctuary of God; it has to be protected from the world and not thrown to the dogs. It is therefore the living word, the Word of God, which he speaks as it pleases him. Costly grace confronts us as a gracious call to follow Jesus, it comes as a word of forgiveness to the broken spirit and the contrite heart. Grace is costly because it compels a man to submit to the yoke of Christ and follow him; it is grace because Jesus says: “My yoke is easy and my burden is light.”
–The Cost of Discipleship (New York: Touchstone, 1995), 45.
Praise God that in his perfect plan he has chosen to call sinners out of darkness and into his marvelous light (1 Peter 2:9)! A god who justifies sin is capricious; a God who justifies sinners is gracious. We have not been justified by a faith in nothing–we are justified by faith in Jesus. He is the Jesus who finds each of us mending our nets by the seaside and graciously commands us, “Follow me!” He is the mysterious rabbi who sought us out at our tax booth and simply said, “Follow me!” The cost of discipleship is death to self. The reward of discipleship is life in Jesus Christ. Grace is costly. But would you want bargain priced grace if it couldn’t save?
