Dietrich Bonhoeffer in The Cost of Discipleship, Christianity Today, February 7, 1994, p. 39
Cheap grace is the grace we bestow on ourselves. Cheap grace is the preaching of forgiveness without requiring repentance, baptism without church discipline, communion without confession. Cheap grace is grace without discipleship, grace without the cross, grace without Jesus Christ, living and incarnate.
Costly grace...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.