In Mexico, Christmas festivities officially begin with the Posadas, a series of nine parties occurring every day from the 16th until the 24th of December. Posadas are said to have been invented by the Spanish priests who in their attempt to convert the locals to Catholicism began holding nine masses before Christmas due to the similar timing of the celebration of the birth of the Aztec god of war, Huitzilopochtli. This gave way to the syncretism of both traditions, melding both the Aztec and Catholic holidays into one.
Posadas occur in the evenings, consisting of a reenactment of Mary and Joseph asking for lodging before arriving at the manger. During this reenactment, half of the people stay inside, these are the innkeepers, and the other half goes outside singing and asking for lodging in a candlelit procession that lasts until they reach the place of the party (where the innkeepers are). Once they let them in, the party begins. During the party, Christmas carols are sung, fruit punch is consumed, and a star-shaped piñata is broken.
The piñata was originally used just after the Conquest by Spanish priests recently arrived in New Spain–as an evangelization tool for the indigenous population. Given that the Spanish spoke no indigenous language and the natives did not speak Spanish, this graphic illustration of sin and redemption made an enormous impact.
Although piñatas have largely lost their religious connotations and are now made in a wide variety of shapes, the traditional piñata is star-shaped and has 7 points, symbolizing the seven deadly sins that are broken by the stick, representing the strength and faith in God. The person attempting to break the piñata must be blindfolded. Once the piñata is broken, the filling, consisting of traditionally candy, fruits and peanuts, is released for everyone to enjoy.