Matthew 5:20 "For I say unto you, That except your righteousness shall exceed the righteousness of the scribes and Pharisees, ye shall in no case enter into the kingdom of heaven."
"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. It is a righteousness under the cross, it belongs only to the poor, the tempted, the hungry, the meek, the peacemakers, the persecuted who endure their lot for the sake of Jesus; it is the visible righteousness of those who for the sake of Jesus are the light of the world and the city set on the hill. This is where the righteousness of the disciple exceeds that of the Pharisees; it is grounded solely upon the call to fellowship with Him who alone fulfils the law. Their righteousness is righteousness indeed, for from henceforth they do the will of God and fulfil the law themselves. Again, it is not enough to teach the law of Christ, it must be done, otherwise it is no better than the old law. In what follows the disciples are told how to practise this righteousness of Christ. In a word, it means following Him. It is the real and active faith in the righteousness of Christ. It is the new law, the law of Christ." —Dietrich Bonhoeffer (1906–1945)
Excerpt taken from The Cost Of Discipleship by Dietrich Bonhoeffer, SCM Press Ltd. published 1959, p. 125