Just for information, the Catholic Catechism on the Law:
http://www.usccb.org/catechism/text/pt3sect1chpt3.htm#art1

"1968: The Law of the Gospel fulfills the commandments of the Law. The Lord's Sermon on the Mount, far from abolishing or devaluing the moral prescriptions of the Old Law, releases their hidden potential and has new demands arise from them: it reveals their entire divine and human truth. It does not add new external precepts, but proceeds to reform the heart, the root of human acts, where man chooses between the pure and the impure,22 where faith, hope, and charity are formed and with them the other virtues. The Gospel thus brings the Law to its fullness through imitation of the perfection of the heavenly Father, through forgiveness of enemies and prayer for persecutors, in emulation of the divine generosity."

"1971: To the Lord's Sermon on the Mount it is fitting to add the moral catechesis of the apostolic teachings, such as Romans 12-15, 1 Corinthians 12-13, Colossians 3-4, Ephesians 4-5, etc. This doctrine hands on the Lord's teaching with the authority of the apostles, particularly in the presentation of the virtues that flow from faith in Christ and are animated by charity, the principal gift of the Holy Spirit. "Let charity be genuine. . . . Love one another with brotherly affection. . . . Rejoice in your hope, be patient in tribulation, be constant in prayer. Contribute to the needs of the saints, practice hospitality."29 This catechesis also teaches us to deal with cases of conscience in the light of our relationship to Christ and to the Church."

"1973: Besides its precepts, the New Law also includes the evangelical counsels. The traditional distinction between God's commandments and the evangelical counsels is drawn in relation to charity, the perfection of Christian life. The precepts are intended to remove whatever is incompatible with charity. The aim of the counsels is to remove whatever might hinder the development of charity, even if it is not contrary to it."

"1975: According to Scripture the Law is a fatherly instruction by God which prescribes for man the ways that lead to the promised beatitude, and proscribes the ways of evil."