Epiphany on the Christian calendar is celebrated on January 6, the 12th Day of Christmas. The term, epiphany, means recognition.
For us, epiphany is demonstrated by the wise men guided by the star as they travel toward Bethlehem. There they, outsiders that they are, recognize the new King. The old king can't find the child by himself. Refer to Matthew 2:1-12 for details.
So, epiphany is the occasion for us to remember that outsiders recognized the Christ child.
Paul says to the Ephesians, and through them to us: People that we religious types did not once think should be included, well, I've been sent to tell you that they, too, are indeed included. They share in the inheritance we claim, they are family; the good news is for them as well as for us.
Give the king your justice, O God, and your righteousness to a king's son....From oppression and violence he redeems their life; and precious is their blood in his sight (Psalm 71:1, 13)
Of this gospel I have become a servant acording to the gift of God's grace that was given me by the working of his power (Ephesians 3:7).