Jesus has accomplished—to put it another way, God has accomplished through Jesus—what Israel failed to accomplish. God’s own covenant faithfulness is thus unveiled at last, an event to which the law and prophets pointed but that they could not bring about. The “faithfulness” of the Messiah, the subject matter of the gospel itself, denotes specifically his death, seen as the culmination of his whole “obedience.” This faithful obedience (or obedient faithfulness) was the means of dealing with sin and hence of creating a forgiven people. The badge of membership in the renewed people of God is faith, not works of the Torah, which would have restricted apparent membership to Jews and proselytes and would in any case have condemned everyone (since all alike are sinful). However, since the gospel of Jesus thus creates a single family for the one God Jews and Gentiles alike, the Torah itself, in which confession of this one God is central, is strangely fulfilled.
N. T. Wright. Romans. (NIBC): 413.