As opposed to the Mosaic Law, Jesus, in the Sermon on the Mount, puts the emphasis first and foremost on a person's interior; that is, on his thoughts and desires. As the saying goes: “Sow a thought, reap an action; sow an action, reap a habit; sow a habit, reap a character; sow a character, reap a destiny.” But in the absence of God's presence in souls, the Mosaic Law was powerless to restore morality. It was an exterior system of rituals which had more symbolic value than anything else. But with the coming of the Holy Spirit, a new spiritual order would be forthcoming.
The prophet Ezekiel prophesied the following: “I will give you a new heart and place a new spirit within you, taking from your bodies your stony hearts and giving you natural hearts. I will put my spirit within you and make you live by my statutes, careful to observe my decrees.” Jesus came to fulfill this passage from the prophet Ezekiel through his public ministry, his death and resurrection and the sending of his Spirit from heaven. In the Sermon on the Mount, he raises the moral aim of his followers. With the impending infusion of the Holy Spirit into willing souls, Christians would be given a new moral power; as such, the demands of the moral law would be elevated.
It is important to understand that the new family of God would not only be given a new law but would also have a divine model in which to imitate. Nevertheless, the observance of the moral law and the imitation of his example would prove to be insufficient. In the New Covenant, the people of God would be called to live the very life of Christ. The interior life of God- which is none other than the Holy Spirit -is communicated through the Sacraments. From this union with God, we can think with Christ and live as he did.
