The gospel of Matthew presents a summary of the teaching of Jesus in what has become known as the Sermon on the Mount. In verse 17 of chapter 5 Jesus says, "Do not suppose that I have come to abolish the law and the prophets; I did not come to abolish, but to complete." If we have read the letters of Paul, we will realize that this doesn't sound much like the gospel Paul preached. "Truly I tell you," Jesus adds in the gospel of Matthew, "so long as heaven and earth endure, not a letter, not a dot, will disappear from the law until all that must happen has happened." (Mt. 5:18)
Because the examples given in the Sermon on the Mount concern moral laws, the statement in verse 18 is not taken literally by Christians to include all Jewish law. In the Sermon on the Mount Jesus emphasizes the relationships among his followers. Keeping the law and the prophets mean living holy and loving lives. This is why asking forgiveness from those we have offended is our highest obligation and the core of the prayer Jesus taught his disciples (Mt. 6:9-13).
Grace and peace...Bob