As the power of the Roman Empire faded in the first centuries of the Common Era, worshiping the Emperor and Roman gods became less prevalent. A new faith, Christianity, developed from Judaism, a religion practiced initially in a remote outpost of the Empire called Judea.
After the death of a holy man named Jesus in about 30CE, his followers spread the message of Christianity to cities throughout the Empire. In Christianity’s early history, it was a Roman citizen’s civic obligation to honor the Emperor and the Roman pantheon of gods and goddesses. The Roman government often persecuted Christians because the Christians believed honoring anything except their one God would lead to damnation. Emperor Nero blamed Christians for starting the Great Fire of Rome in 64CE. Emperor Decius declared Christians to be “enemies of Rome.” There are stories of Roman officials ordering Christians to be thrown to wild beasts for refusing to renounce their faith. Despite Roman authorities’ efforts to suppress it, Christianity continued to grow.
Over time, many traditional Roman practices merged with Christian celebrations. Christians began to celebrate the birth of Jesus in December, when Romans traditionally celebrated the sun’s birth after the longest night of the year.
Emperor Constantine decreed that Christians could practice their beliefs without oppression in CE311. By 325, Constantine called Church leaders to a meeting in Nicaea, in present-day Turkey, to standardize Christian teaching throughout the Empire. Forty-three years after Constantine’s death, Emperor Theodosius declared Christianity to be the Empire’s official religion. The standards set by Constantine at Nicea were to be considered official, and all other Christian teachings were heresy. Heresy is a belief that contradicts or defies established religious teachings.