109 It was necessary, then, that spiritual things should be made known as in a mirror and in a riddle; “For now we see by means of a mirror, but then face to face.” Now we war after the flesh, then in the Spirit we shall see the divine mysteries. Let, then, the character of the true law be expressed in our manner of life, who walk in the image of God, for the shadow of the Law has now passed away. The carnal Jews had the shadow, the likeness is ours, the reality theirs who shall rise again. For we know that according to the Law there are these three, the shadow, the image or likeness, and the reality; the shadow in the Law, the image in the Gospel, the truth in the judgment. But all is Christ's, and all is in Christ, Whom now we cannot see according to the reality, but we see Him, as it were, in a kind of likeness of future things, of which we have seen the shadow in the Law. So, then, Christ is not the shadow but the likeness of God, not an empty likeness but the reality. And so the Law was by Moses, for the shadow was through man, the likeness was through the Law, the reality through Jesus. For reality cannot proceed from any other source than from reality.
Source: On the Death of Satyrus (New Advent)