The Jewish Christians respected highly Moses and the Mosaic Law. So Matthew enhances the position of Jesus and his teachings without negating Moses' teachings. Here Jesus did not deny the validity of the law but emphasized that the law itself needs to be completed and perfected (vs 17 & 18). So Jesus came to fulfill and not to abolish the law and the prophets.

By fulfillment, Matthew means radicalizing and sharpening the demands of the law in accordance with the proclamation of the Kingdom. It was not to observe the letter of the law but the spirit of the law. V.19 stresses on the teachers of the law, and those who follow the commandments and teach them accordingly.

So Jesus' response and his new and perfected law must be greater than the law of Moses. This also means that to follow Jesus' law is to do God's will and this ought to be the pattern of our life as disciples of Jesus.

As in the first reading as regards our faith, our personal experience of God affirms what is in the spirit of the law. This is not to be kept for oneself but to pass on to the younger generations so that they will have the experience of a personal God in their lives.