Christmas as a celebration of the nativity

Adorazione del Bambino (Adoration of the Child) (1439-43), a mural by Florentine painter Fra Angelico.The Nativity of Jesus refers to the Christian belief that the messiah was born to the Virgin Mary. The story of Christmas is based on the biblical accounts given in the Gospel of Matthew, namely Matthew 1:18-Matthew 2:12 and the Gospel of Luke, specifically Luke 1:26-Luke 2:40. According to these accounts, Jesus was born to Mary, assisted by her husband Joseph, in the city of Bethlehem. According to popular tradition, the birth took place in a "stable", surrounded by farm animals, though neither the “stable” nor the animals are mentioned in the Biblical accounts. However, a "manger" is mentioned in Luke 2:7 where it states "She wrapped him in cloths and placed him in a manger, because there was no room for them in the inn." Shepherds from the fields surrounding Bethlehem were told of the birth by an angel, and were the first to see the child. Christians believe that the birth of Jesus fulfilled many prophecies made hundreds of years before his birth.

The word "Christmas" originated as a contraction of "Christ's mass." It is derived from the Middle English Christemasse and Old English Cristes mæsse, a phrase first recorded in 1038. After the conversion of Anglo-Saxon Britain in the very early 7th century, Christmas was referred to as geol,[4] the name of the pre-Christian solstice festival from which the current English word 'Yule' is derived. In early Greek versions of the New Testament, the letter Χ (chi), is the first letter of Christ (Χριστός). Since the mid-sixteenth century Χ, or the similar Roman letter X, was used as an abbreviation for Christ. Hence, "Xmas" is often used as an abbreviation for Christmas.

Remembering or re-creating the Nativity is a central way that Christians celebrate Christmas. The Eastern Orthodox Church practices the Nativity Fast in anticipation of the birth of Jesus, while much of the Western Church celebrates Advent. In some Christian churches, children perform plays re-telling the events of the Nativity, or sing carols that reference the event. Some Christians also display a small re-creation of the Nativity, known as a Nativity scene, in their homes, using figurines to portray the key characters of the event. Live Nativity scenes are also performed, using actors and live animals to portray the event with more realism.

Nativity scenes traditionally include the Three Wise Men, Balthazar, Melchior, and Caspar, although their names and number are not referred to in the Biblical narrative, who are said to have followed a star, known as the Star of Bethlehem, found Jesus, and presented gifts of gold, frankincense, and myrrh.

In the U.S., Christmas decorations at public buildings once commonly included Nativity scenes. This practice has led to many lawsuits, as groups such as the American Civil Liberties Union believe it amounts to the government endorsing a religion. In 1984, the U.S. Supreme Court ruled that a city-owned Christmas display, even one with a Nativity scene, does not violate the First Amendment.