Christmas is one of the most important days of the Church year, second only to Easter itself. It is the feast of the incarnation, the feast of God becoming flesh (the Latin “in carne” means “enfleshment”). It is a uniquely Christian teaching, the Divine choosing to become one of us. Because of this belief, God is not only Transcendent, but also wholly Immanent, Emmanuel (God-with-us). While remaining Transcendent (meaning we must rise above our present condition to reach Him), He is at the same time Immanent (meaning He is with us as we rise toward Him).

Every Eucharist is like Christmas where the bread and wine are transformed into His flesh, His Body and Blood, and, in a sense, He is born anew on the altar.

The liturgical season of Christmas begins with the vigil Masses on Christmas Eve and concludes on the Feast of the Baptism of the Lord. During this season, we celebrate the birth of Christ into our world and into our hearts, and reflect on the gift of salvation that is born with him…including the fact that he was born to die for us.

The Christmas tree and the Nativity scene are popular symbols of the season and a tradition in many Christian homes. It is also traditional to exchange Christmas gifts with family and friends as a way to honor God the Father’s gift of his only son to the world. Having received the gift of Christ, we naturally want to pass that gift along to our loved ones.

The Octave of Christmas is a time for us to enter into the stories of special saints who are associated with the birth of our Lord because of their innocence: our first martyr and the disciple Jesus loved.

The Birth of Christ – Dec. 25, Tuesday is Christmas Day, the first day in this eight-day celebration of the Octave of Christmas. We take joy in the story of the nativity and of Our Savior’s entrance into the world in the most humble of ways. Families are encouraged to read together the infancy narrative from the Gospel of Luke, and reflect on the gift of salvation that Jesus brings.

St. Stephen – Dec. 26
December 26, the day after Christmas, is the Feast of St. Stephen, the first martyr. The reading from Acts takes us into the story of his being stoned by an infuriated crowd.

St. John, the Apostle – Dec. 27
December 27 we traditionally celebrate the Feast of St. John, Apostle and Evangelist. This apostle is associated with the wonderful tradition and writings that bear his name. This week, our reflection is framed by the wonderful words of the First Letter of John and the story from the Fourth Gospel of Simon Peter and “the other disciple whom Jesus loved” who ran to find the empty tomb on Easter morning. Today, pray about how you can better live out your own vocation and calling.

The Holy Innocents – Dec. 28
On December 28, we celebrate the Feast of the Holy Innocents. This celebration takes us back into the infancy narrative of Matthew. The account of how Jesus begins his journey to become one with us, is powerfully told as a journey of Jesus’ entering into the journey of his people, with the flight into Egypt and the horrible slaughter of the innocent children. On this Feast of Holy Innocents, pray for greater respect for all life from conception until natural death.

St. Thomas Becket – Dec. 29
On December 29, we celebrate the Fifth Day within the Octave of the Nativity of the Lord — and the feast of St. Thomas Becket, who was a bishop, martyred for defending the principles of religious liberty. Ask St. Thomas for protection of our religious liberty from contemporary threats.

The Holy Family – Dec. 30
The Feast of the Holy Family is often celebrated on the Sunday after Christmas. When a Sunday does not occur between December 25 and January 1, this feast is celebrated on December 30 with only one reading before the Gospel. This time allows us to reflect on Joseph, Mary, and Jesus, and ask ourselves what graces they could offer us.
This also allows us a bit more time to reflect upon the Christmas story, including the everyday reality that was part of their lives as family – the patience, give and take, the self-sacrifice and the love that was a part of their very human interaction together, throughout what we call “the hidden life” of Jesus. That can include all the hidden years of Jesus’ life, what their village was like and what ways they spoke with each other, as well as what difficulties they might have experienced. Today, participate in Mass as a family and enjoy a special treat together afterward!

Mary, Mother of God – Jan. 1
On New Year’s Day, the octave day of Christmas, the Church celebrates the Solemnity of Mary the Holy Mother of God. It is the highest title of the Blessed Virgin Mary: Theotokos, Mother of God. This title was given to Mary at the Council of Ephasus in 431 A.D.

The Epiphany – Jan. 6
In most countries and dioceses, the Feast of the Epiphany is transferred to the Sunday between Jan. 2 and Jan. 8. This year, we celebrate the Epiphany on Sunday, Jan. 6.
The Epiphany marks the arrival of visitors, traditionally identified as magi, to where Jesus was born. Their visit is an important reminder that Jesus came to bring salvation to all nations.
This marks a week of gratitude — growing in a sense of freedom and joy over the gift we have been given to know God’s love for us and presence with us more deeply.
However, if our celebration of the days before Christmas and Christmas Day itself were busy or even difficult, then this can be days of recovery and added time to let Our Lord come into our lives where we need him to come the most.

Source: http://www.usccb.org/prayer-and-worship/liturgical-year/christmas/index.cfm