The Feast of the Epiphany of Our Lord Jesus Christ is one of the oldest Christian feasts, though, throughout the centuries, it has celebrated a variety of things.
Epiphany comes from a Greek meaning “to reveal,” and all of the various events celebrated by the Feast of the Epiphany are revelations of Christ to humanity.
Epiphany originally celebrated four different events, in the following order of importance: the Baptism of the Lord; Christ’s first miracle in the changing of water into wine at the wedding in Cana; the Birth of Christ; and the visitation of the Wise Men. Each of these is a revelation of God to humankind.
Eventually, Western Christians separated out the celebration of the Nativity into Christmas; the Baptism of the Lord to the Sunday after January 6 (unless Epiphany falls on Sunday, January 7 or 8 then the Baptism of the Lord is celebrated the next Monday); and the wedding at Cana to the Sunday following the Baptism of the Lord.
The Feast of Epiphany, therefore, commemorates the manifestation, the revelation, of God through Christ to the whole world (that is, to the Gentiles and not just the Jews) symbolized by the visit of the Magi to the Christ child, when they worshipped him and gave him gifts. These Wise Men were guided through darkness by the light of the star. The star is seen as a sign that leads the wise to Jesus. (10:6)