According to Matthew, Jesus speaks as a true teacher of the Law, as one who, as a descendant of Abraham and of Moses, and of the prophets, has inherited the Law, and now shows us baptized believers, disciples of Christ and of his Gospel, that the Law of God applies to all aspects of our life, that the Law of Christ must direct our behavior, and all of our relationships. Jesus, according to Matthew, is telling us that to truly fulfill the Law, we must allow it into our hearts.
Now, in the bible, the heart is the core of our being, the source of all our actions and decisions. In other words, Jesus shows how true righteousness before God consists not in carrying out a set of religious rules or practices or rituals, because the Law as received from God and transmitted down through the generations, which is the Law of Christ, is a living practice, a true way of life, a path of wisdom.
Because wisdom is of God, it leads us to love, and compassion, and to peace, in all aspects, all areas of our life. So, what Jesus says today goes toward the heart of our life itself. The true fulfillment of the Law, says Jesus, is not obligatory but relational: Our true happiness, our deepest peace, and greatest solidarity, comes from honoring one another, respecting and loving one another.
This is why Jesus points at those areas of our life where we most tend to not see the point, where we even try to take shortcuts.
For example, Jesus tells us that anger, that powerful emotion we all tend to struggle with the most, is to be checked way before it leads to acts of violence, like killing. Jesus is saying, “Go there, to your core, your heart, for it may be saying something you need to know. Maybe deep down inside you, there is chaos, or hatred, or bitterness, and resentments, and jealousy, but if you acknowledge them, you will not act out in destructive ways, toward yourself, or toward others.
Still another area that Jesus points out is that aspect of ourselves that we seldom want to talk about, but that affects us all, and with which every human being is endowed: Sexual desire, the need, for physical and sexual intimacy with another, that very human, creative drive to connect with others, and to love ourselves. In a world where only a man had the right to a divorce, and could at any time leave his wife, even if it meant leaving her penniless or homeless, Jesus takes us back to the beginning, to that first spark of lust that expresses itself, first by objectifying women by seeing them as objects for lust, and ends eventually by ignoring their human dignity, and their freedom, and to acts of violence against them.
Jesus points out, too, that having to swear, that is, to take an oath, to prove our honesty, is misdirected, and off point. If we live a life of transparency, and if we stay present to our life, and to the life of others, without judging, but only seeing, then we will never need to lie, or to cover up something with a lie, or to call upon God to prove our truthfulness.
So, then, in the service of the Lord, as members of the living, resurrected body of Christ, we are to renounce, we are to “cut off,” whatever becomes an obstacle to our original freedom, our original joy, and natural state of rest in God, and love for one another. We are to allow God, and Christ in God, to bear the fruit of the Spirit in us, with us, and through us.