328 • Part III. Christian Morality: The Faith Lived
culture, or era of time may attempt to suppress it, the fundamental prin-
ciples of the natural law never die and soon reappear, even where they
were once rejected.
We come to know God’s plan for us not only through an under-
standing of our human nature and his created order but also because
he speaks directly to us. In the Old Testament, God communicated to
Moses the Ten Commandments. This Law prepared the world for the
Gospel. Christian tradition reveres this Law as holy but in need of God’s
grace for its fulfillment. It is like a teacher who can tell us what to do but
is not able to give us the strength to perform it. Nonetheless, we honor
this Law as an aid to God’s people on the way to the Kingdom. It pre-
pared people to receive Christ.
In Jesus, Revelation comes to us in its fullness. His words shed light
on the human condition in a way that transcends and fulfills the law
written in our heart and God’s plan revealed in the Old Testament.
In the Sermon on the Mount, Jesus revealed the full meaning of the
Old Testament Law. “Do not think I have come to abolish the law and
the prophets. I have come not to abolish but to fulfill” (Mt 5:17). Christ’s
teaching releases the hidden meaning of the Old Law and reveals its
Divine Truth and human truth. Jesus established the law of love because
love is poured into our hearts by the Holy Spirit. It is a law of grace, as
we note in the next section.
Grace and Justification
God also directly assists us in living our moral life through the divine
gift of grace and justification, first bestowed upon us in Baptism when
we become members of the Church. We are justified—cleansed from
our sins and reconciled to God—through the power of the Holy Spirit.
Justification is both the Spirit’s work in bringing us forgiveness of sins
and our acceptance or reception of the holiness of God, which we call
sanctification through participation in divine life. Christ’s Passion mer-
ited justification for us. We receive justification in Baptism and become
friends of God. We are thus conformed to the righteousness of God who
justifies us. Justification’s goal is God’s glory and the glory of Christ and
the gift of eternal life. It is a work of God’s mercy (cf. CCC, no. 2020).