CCC 1966
© Libreria Editrice Vaticana Source: vatican.va
The New Law is the grace of the Holy Spirit given to the faithful through faith in Christ. It works through charity; it uses the Sermon on the Mount to teach us what must be done and makes use of the sacraments to give us the grace to do it:
If anyone should meditate with devotion and perspicacity on the sermon our Lord gave on the mount, as we read in the Gospel of Saint Matthew, he will doubtless find there . . . the perfect way of the Christian life.... This sermon contains ... all the precepts needed to shape one's life. St. Augustine, De serm. Dom. 1, 1: PL — Patrologia Latina (Migne).
Read the full chapter 3. God’s Salvation: Law and Grace ¶1949–2051