From Pope St. John Paul II’s encyclical Veritatis Splendor (1993):
The Church gratefully accepts and lovingly preserves the entire deposit of Revelation, treating it with religious respect and fulfilling her mission of authentically interpreting God’s law in the light of the Gospel. In addition, the Church receives the gift of the New Law, which is the “fulfilment” of God’s law in Jesus Christ and in his Spirit. This is an “interior” law (cf. Jer 31:31-33), “written not with ink but with the Spirit of the living God, not on tablets of stone but on tablets of human hearts” (2 Cor 3:3); a law of perfection and of freedom (cf. 2 Cor 3:17); “the law of the Spirit of life in Christ Jesus” (Rom 8:2). Saint Thomas writes that this law “can be called law in two ways. First, the law of the spirit is the Holy Spirit . . . who, dwelling in the soul, not only teaches what it is necessary to do by enlightening the intellect on the things to be done, but also inclines the affections to act with uprightness . . . Second, the law of the spirit can be called the proper effect of the Holy Spirit, and thus faith working through love (cf. Gal 5:6), which teaches inwardly about the things to be done . . . and inclines the affections to act”.84
Even if moral-theological reflection usually distinguishes between the positive or revealed law of God and the natural law, and, within the economy of salvation, between the “old” and the “new” law, it must not be forgotten that these and other useful distinctions always refer to that law whose author is the one and the same God and which is always meant for man. The different ways in which God, acting in history, cares for the world and for mankind are not mutually exclusive; on the contrary, they support each other and intersect. They have their origin and goal in the eternal, wise and loving counsel whereby God predestines men and women “to be conformed to the image of his Son” (Rom 8:29). God’s plan poses no threat to man’s genuine freedom; on the contrary, the acceptance of God’s plan is the only way to affirm that freedom.
84 In Epistulam ad Romanos, c. VIII, lect. 1.
— Veritatis Splendor 45