N.B. for readers outside the United States: The traditional date for the celebration of Epiphany is January 6, but here in the United States, this feast is “translated” (yep, that’s how you say it) each year to the Sunday which falls between January 2 and January 8 (i.e. today). The Baptism of the Lord is celebrated on the following day (Monday).
“The Epiphany recalls a plurality of events whose object is the manifestation of the Lord: particularly the adoration of the Magi, who recognize in Jesus the awaited Messiah, but also the Baptism in the river Jordan with its theophany – the voice of God from heaven – and the miracle at the Wedding Feast of Cana, as the first ‘sign’ wrought by Christ.
“A most beautiful antiphon from the Liturgy of the Hours unites these three events around the theme of the marriage between Christ and the Church: ‘Today the Church hath been joined to her heavenly Spouse, for Christ hath washed away her sins in the Jordan; the Magi hasten with gifts to the royal nuptials, and the guests are gladdened with wine made from water’ (Antiphon from Lauds). We could almost say that, in the feast of Christmas, it is the hiddenness of God in the humility of the human condition, in the Child of Bethlehem, which is underscored. The Epiphany, instead, emphasizes His Self-manifestation, God’s appearing by means of this same humanity.”
– Pope Benedict XVI, General Audience, January 6, 2012
You can read the Holy Father’s entire catechesis on Zenit.org.