Catechism of the Catholic Church §1967 — excerpt
The Law of the Gospel "fulfills," refines, surpasses, and leads the Old Law to its perfection. In the Beatitudes, the New Law fulfills the divine promises by elevating and orienting them toward the "kingdom of heaven."
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.