Here is Pastor Gary Gilley's review...
The Cost of Discipleship by Dietrich BonhoefferBonhoeffer, who died because of his principles in a Germany concentration camp in 1945, is one of the most frequently quoted individuals by evangelical leaders. This has always surprised me given the fact that Bonhoeffer was a Christian humanist with neo-orthodox leanings. Nevertheless, I decided to read for myself this, his most well known book.
Bonhoeffer's greatest contribution to the Christian community is his teachings on what he calls "cheap grace." "Cheap grace," he writes, "means the justification of sin without the justification of the sinner" (p.46). In a statement that would strike a great blow against easy-believism of our day he says, "Cheap grace is the preaching of forgiveness without requiring repentance, baptism without church discipline, Communion without confession, absolution without personal confession. Cheap grace is grace without discipleship, grace without the cross, grace without Jesus Christ, living and incarnate" (p.47). To these thoughts, and the theology behind them, we say a hardy "amen."
On the other hand, in addition to his humanistic and neo-orthodox tendencies mentioned above, The Cost of Discipleship clearly revealed other major problems. Most disturbing of which is his belief concerning sacramental regeneration. Bonhoeffer takes the traditional Lutheran view that grace is dispensed through the sacraments of baptism (most often infant baptism) (pp. 254-262) and the Lord's supper (pp. 263-276). In other words, it is through these means that one is born again. Additionally he believes that a true Christian can lose his salvation (p. 329). These are grave errors that must be factored into any understanding of Bonhoeffer's teachings.
While Bonhoeffer supplies some thoughts worth considering, his false teachings are too many and too real to ignore.