The law, righteousness and calling

As Bonhoeffer continues his exegesis in chapter 8 of Discipleship, Bonhoeffer begins to expound Jesus' teaching on the Law in Matt 5:17-20.
Bonhoeffer argues that Jesus is calling the disciples to the Old Testament law. Every jot and tittle of it must be obeyed, indeed in such a fashion that the disciples must have a 'better righteousness' than that of the Pharisees. The marvelous advantage for the disciples over the Pharisees however, is that 'between the disciples and the better righteousness demanded of them stands the Person of Christ, who came to fulfill the law of the old covenant'.¹ Rather than the law standing between Jesus and the disciples, Jesus stands between the disciples and the law, fulfilling it perfectly because of his 'perfect communion with God'.
Bonhoeffer goes on to suggest then, that such teaching from Jesus in no way frees the disciples from the law, but instead validates 'his demand that they should fulfill it'. The disciple must 'do' and 'teach' and their righteousness must exceed (περισσεύσῃ) that of the Pharisee, something that is of course only possible by virtue of the fact that Jesus, with whom they have communion stands between the disciple and the law. 'The righteousness it demands is already there, the righteousness of Jesus which submits to the cross because that is what the law demands'.²
What does all this have to do with calling? For Bonhoeffer, the call of God is the means by which this righteousness is given to the disciple: 'Of course the righteousness of the disciples can never be a personal achievement; it is always a gift, which they received when they were called to follow him. In fact their righteousness consists precisely in their following him, and in the beatitudes the reward of the kingdom of heaven has been promised to it'.³

1. Bonhoeffer, Discipleship, 74-75.
2. Bonhoeffer, Discipleship, 77.
3. Bonhoeffer, Discipleship, 77.