Saint Augustine, in a sermon given in about A.D. 412, speaks of the Catholic celebration of Epiphany on January 6. Saint Augustine had an ongoing debate concerning this feast with the Donatists, a heretical group that denied penance after mortal sin and rejected the sacraments of evil clergy as invalid.
An interesting fact about this moment in history is that the Donatist heretics celebrated December 25 as the birthday of Christ since they rendered the celebration of Christmas as an Apostolic tradition. However, the Donatists rejected the feast of the Epiphany. The Donatists claimed that the Feast of the Epiphany was a liturgical innovation whereas Christmas was not. Consequently, they refused to celebrate Epiphany.
Augustine's city of Hippo in North Africa was still a stronghold for the heretical Donatists. Apparently, by A.D. 412 the celebration of Epiphany on the part of Catholics was a line in the sand demarcating the true Catholics from the false Donatists who claimed to be the "true Church."
Saint Augustine, pray for us.
Happy Feast of the Epiphany!