VATICAN CITY (EWTN News/CNA)—The joy of the Christmas season is the unparalleled union of God and man, said Pope Benedict XVI at the first general audience for 2012.

“Humanity’s dream which began in the Garden of Eden, we want to be like God, is realized in an unexpected way, not through the greatness of man, who cannot make himself God, but through the humility of God, who came down among us in his humility, raising us to the true greatness of his being,” the Pope said to the 7,000 people in the Vatican’s Paul VI Hall on Jan. 4.

This is the reason why “our first reaction to the birth of Jesus should be one of joy,” he said, because we now know “that God has assumed our humanity in order to make us sharers in his own divine life.”

This, he explained, is what theologians refer to as the “admirabile commercium,” or “wondrous exchange,” that took place in Bethlehem.

Today we experience this exchange “most powerfully in the Eucharist,” which invites us “to recognize our lofty dignity as God’s adopted sons and daughters,” he said.

The incarnation of Christ also brings great joy, as it “dissipates the shadows of the world and fills the holy night with a celestial splendor, spreading the radiance of God the Father over the faces of men, even today.”

This light was foreshadowed by God’s covenant with the Jewish people, where he had “spoken and intervened in history through messengers and signs.”

But at his birth in Bethlehem, Jesus appeared and “came out of his inaccessible light in order to illuminate the world,” the Pope said. He added, Christ has given this joy and light to the Catholic Church “to be illuminated and thereby to spread it in all its splendor.”

Pope Benedict said that this challenges individual Catholics to “welcome the newborn Savior” into their hearts so that their lives can be “transformed by his gifts of joy, newness and light,” and then share them with the world.

“Christmas,” concluded the Pope, “means pausing to contemplate the Child, the mystery of God who became man in humility and poverty.”

It also means, above all, “making that Child, who is Christ the Lord, part of ourselves,” so that his feelings, thoughts and actions are “our feelings, thoughts and actions.”

Therefore, to celebrate the Christmas season “is to express the joy, novelty and light which that birth brought into our lives; that we too may bring others joy, true newness and the light of God.”

Pope Benedict ended the audience by singing the Our Father in Latin and imparting his blessing on the crowd.