This feast was celebrated in the East as early as the third century and it spread to the West towards the end of the fourth century. The word "Epiphany" means "manifestation." As at Christmas it is the mystery of a God Who makes Himself visible, but it is no longer only to the Jews that He shows Himself: "It is to the Gentiles on this day that God reveals His Son" (Collect).
And Isaias in a grand vision perceives the Church under the figure of Jerusalem, where "the kings and the nations abound, the multitude who inhabit the borders of the sea and the strength of the Gentiles. They come from afar with their numerous caravans, singing the praises Of the Lord and bringing Him gold and frankincense" (Epistle) "The kings of the earth shall adore God, and all nations shall serve Him "'(Offertory).
While at Christmas we extolled the union of the divinity with the humanity of Christ, so the Epiphany celebrates the mystic union of the souls of men with Jesus.
The liturgy of this day commemorates a triple manifestation of the glory of Christ. To the worshipping Magi He appears as King of our hearts; in the Waters of the Jordan He is declared the Son of God, and at Cana He demonstrates His power over the elements. "Today the Church is united to her heavenly Spouse, for Christ has washed away her sins in the Jordan the Magi hasten with their gifts to the royal nuptials, and the guests drink with joy the water changed into wine. Alleluia."
At St. Peter's, where are the relics of the Church's first visible head, the liturgical celebration of the entry of the Gentiles into the Church takes place. "In the adoring Mass," says Pope St. Leo the Great, "let us acknowledge the first-fruits of our own calling and faith; and let us commemorate with hearts full of joy the foundations of this our blessed hope. For from this moment we have begun to enter our Heavenly patrimony."
It is the traditional Catholic custom to take chalk blessed by the priest and write above the doors of our homes the year in Roman numerals and below that C + 20 + M + the year in Arabic numeral + B. You may also put down 20 + C + M + B + the year (vg. 17). The CMB (Caspar, Melchior, Balthazar the three Magi) represents in Latin: Christus Mansionem Benedicat which translated means "May Christ bless (this) house (home)." By our Faith we pray the Aangel of the Lord will watch over us and all who enter our home throughout the year.
Sources: Saint Andrew Daily Missal and the Marian Missal , 1945