Why December 25th?

Some insights from Christmas in America, a history, by Penne L. Restad

Sometime in the fourth century of the Common Era, the Roman Church began to celebrate a Feast of the Nativity and to do so on December 25th. A variety of issues influenced the decision. Internally, heresies plagued Church authority. Arianism, one of the most threatening, regarded Jesus as a solely human agent of God. The Church insisted on his divinity. By assigning him one human quality – a birthday – it appropriated some of Arianism’s appeal, but sustained Jesus’ place in the Holy Trinity.

The Church had also grown concerned about the increasing popularity of pagan religions and mystery cults in Rome. Each year beginning on December 17, the first day of Saturnalia, and continuing through Kalends, the first day of January, most Romans feasted, gamed, reveled, paraded, and joined in other festivities as they paid homage to their deities. The Church’s alarm deepened when Emperor Aurelian, noticing that the pagan rituals had begun to converge around Mithras, the solar god, decreed in 274 C.E. that December 25, the winter solstice on the Julian Calendar, be kept as a public festival in honor of the Invincible Sun. Rome’s Christians challenged paganism directly by specifying December 25, rather than some other date, as the day for their Nativity Feast.

Exactly when the Church of Rome began to keep Christmas, however, is not known. The first extant reference to the Feast of the Nativity may be as old as 336, in the earliest list of martyrs of the Roman Church. Perhaps Christmas was celebrated even earlier. Some scholars believe that Emperor Constantine (ruled 312-337 C.E.), who had converted to Christianity and built the Vatican atop the hill where the Mithras cult worshipped the sun, may have instituted the festival.