Today, Jesus tells us: «I have come to fulfill the Law» (Mt 5, 17). What is the Law? What is ‘The Prophets’? By the Law and the Prophets, Jesus meant two different sets of books of the Old Testament. The Law refers to the works believed to have been written by Moses; the Prophets, as the name itself indicates, are the works of the Prophets and the Sapiential books.
In Today's Gospel, Jesus refers to those who are considered the summary of the moral code of the Old Testament: The commandments of the law of God. According to Jesus, the Law isn't merely about external principles. It isn't an external imposition, on the contrary. Actually, God's Law corresponds to the ideal of perfection that is deeply rooted in the heart of every man. This is the reason why they who keep the commandments not only achieve the accomplishment of their human aspirations, but also the perfection of christianism, or, in Jesus's words, achieves the perfection of the Kingdom of God. «Whoever obeys them and teaches others to do the same will be great in the kingdom of heaven» (Mt 5, 19).
«But I say to you» (Mt 5,22). The observance of the Law isn't restricted to the letter, since «For the letter kills, but the Spirit gives life» (2Cor 3:6). This is the meaning in which Jesus employs His authority to interpret the Law according to its most authentic spirit. As Jesus interprets it, the Law is extended to its ultimate consequences: the respect for life is connected to the eradication of hate, vengeance and offense; the chastity of the body, to the purity of intentions; the perfection of matrimony depends on fidelity and indissolubility; the truth of the word given starts with the respect for pacts. By observing the law, Jesus «fully reveals man to man himself and makes his supreme calling clear» (Vatican II Council).
The example of Jesus invites us to that perfection of Christian life in which we practice with actions what we preach with words.