The Dec. 8 opening of the Jubilee of Mercy, an Extraordinary Holy Year, coincided with the Solemnity of the Immaculate Conception. The Holy Year will close Nov. 20, 2016 with the Solemnity of Christ the King.
The Jubilee was officially inaugurated by the opening of the Holy Door in St. Peter's Basilica. Pilgrims who pass through the door -- which is only opened during Jubilee years -- can receive a plenary indulgence under the usual conditions.
Pope Francis presided over the rite of the Holy Door's opening before passing through himself. He was followed by retired pontiff Benedict XVI, who attended the rite in one of his rare public appearances.
The opening of the door is meant to symbolically illustrate the idea that the Church's faithful are offered an "extraordinary path" toward salvation during the time of jubilee.
Pope Francis in his homily spoke of the Holy Door in connection to the day's Gospel, which recounts the angel Gabriel announcing to Mary she would be the mother of God.
"We carry out this act, so simple yet so highly symbolic, in the light of the word of God which we have just heard," Pope Francis said.
"That word highlights the primacy of grace...God's grace enfolded her and made her worthy of becoming the Mother of Christ."
When Gabriel entered Mary's home, "even the most profound and impenetrable of mysteries became for her a cause for joy, faith and abandonment to the message revealed to her," the Pope continued.
Pope Francis' reflection in his homily centered on the Immaculate Conception, celebrated Tuesday, and described the feast as an expression of "the grandeur of God's love."
"Not only does he forgive sin, but in Mary he even averts the original sin present in every man and woman who comes into this world."
"The fullness of grace can transform the human heart and enable it to do something so great as to change the course of human history," he said.
The Pope made reference to the day's first Mass reading, the Genesis account of man's fall in the Garden of Eden.
"The words of Genesis reflect our own daily experience: we are constantly tempted to disobedience, a disobedience expressed in wanting to go about our lives without regard for God's will," he said.
"Yet the history of sin can only be understood in the light of God's love and forgiveness. Were sin the only thing that mattered, we would be the most desperate of creatures."
"The promised triumph of Christ's love enfolds everything in the Father's mercy," the Pope said. "The Immaculate Virgin stands before us as a privileged witness of this promise and its fulfillment."
Pope Francis concluded his homily recalling the 50th anniversary of the Second Vatican Council's closing, which is also commemorated Dec. 8. He stressed that the Jubilee of Mercy is a challenge for us to the "openness" inspired by the Council.
The Council was "a genuine encounter between the Church and the men and women of our time," in which the Holy Spirit "impelled the Church to emerge from the shoals which for years had kept her self-enclosed so as to set out once again, with enthusiasm, on her missionary journey."
"Wherever there are people, the Church is called to reach out to them and to bring the joy of the Gospel," the Pope said.
"The Jubilee challenges us to this openness, and demands that we not neglect the spirit which emerged from Vatican II, the spirit of the Samaritan, as Blessed Paul VI expressed it at the conclusion of the Council."
In his Angelus address delivered after the opening of the Holy Door, Pope Francis called the faithful to look on the Immaculate Conception as a reminder that, "in our life, everything is a gift. Everything is mercy."
"May the Blessed Virgin, the first fruits of the saved, the model of the Church, holy and immaculate Bride, loved by the Lord, help us to rediscover the mercy of God more and more, in a way characteristic of Christians."
The Pope said the opening of the Jubilee of Mercy is an occasion to look on the Immaculate Conception "with trusting love, to contemplate her in all her splendor, (and imitate) her faith."
"In the Immaculate conception of Mary, we are invited to recognize the dawn of the new world, transformed from the saving work of the Father and of the Son and of the Holy Spirit."