Christ is the fulfilment of Scripture
“I have not come to abolish, but to fulfil.” The strength and power of these words of the Son of God enclose a profound mystery.
For the Law prescribed works, but it directed all those works towards faith in realities that would be made manifest in Christ: for the Savior's teaching and Passion are the great and mysterious design of the Father's will. Under the veil of its inspired words, the Law made known the birth of our Lord Jesus Christ, his incarnation, Passion and resurrection. The prophets, no less than the apostles, teach us repeatedly that the mystery of Christ had been prepared from all eternity to be revealed in our own times...
Christ did not want us to think that his own works comprised anything other than the Law's demands. That is why he himself insisted: “I have not come to abolish, but to fulfil.” Heaven and earth... will disappear but not the least commandment of the Law, for all the Law and the prophets find their fulfilment in Christ. At the time of his Passion... he declared: “It is finished” (Jn 19:30). And at that very moment every word of the prophets was confirmed.
For this reason Christ declares that not even the least of God's commandments can be cancelled without offending God... Nothing can be more insignificant than the smallest. And humblest of all was the Lord's Passion and death on the cross.