Holy Trinity, fresco by Luca Rossetti da Orta, 1738-9 (St. Gaudenzio Church at Ivrea, Torino)
Trinity Sunday is the sixth Sunday after Pentecost in the Traditional Roman Catholic Church. Trinity Sunday celebrates the Christian dogma of the Trinity, the three Persons of God: the Father, the Son, and the Holy Ghost.In the liturgical Year it represents the second half of the year from "time after Pentecost" until the first Sunday in Advent. In the liturgy we now celebrate the reign of the Holy Ghost , which extends over the universal church and is evidence from Penticost to the end of the world.
History
In the early Church, no special Office or day was assigned for the Holy Trinity. When the Arian heresy was spreading, the Fathers prepared an Office with canticles, responses, a Preface, and hymns, to be recited on Sundays. In the Sacramentary of St. Gregory the Great (P.L., LXXVIII, 116) there are prayers and the Preface of the Trinity. The Micrologies (P.L., CLI, 1020), written during the pontificate of Gregory VII (Nilles, II, 460), call the Sunday after Pentecost a Dominica vacans, with no special Office, but add that in some places they recited the Office of the Holy Trinity composed by Bishop Stephen of Liège (903-20). By others the Office was said on the Sunday before Advent. Alexander II (1061–1073), refused a petition for a special feast on the plea, that such a feast was not customary in the Roman Church which daily honoured the Holy Trinity by the Gloria Patri, etc., but he did not forbid the celebration where it already existed. John XXII (1316–1334) ordered the feast for the entire Church on the first Sunday after Pentecost. A new Office had been made by the Franciscan John Peckham, Canon of Lyons, later Archbishop of Canterbury (d. 1292). The feast ranked as a double of the second class but was raised to the dignity of a primary of the first class, 24 July 1911, by Pius X (Acta Ap. Sedis, III, 351). Since it was after the first great Pentecost that the doctrine of the Trinity was proclaimed to the world, the feast becomingly follows that of Pentecost.
In the Roman Catholic Church it is officially known as the Solemnity of the Most Holy Trinity. Prior to the reforms of the Second Vatican Council, it marked the end of a three-week period when church weddings were forbidden. The period began on Rogation Sunday, the fifth Sunday after Easter. Trinity Sunday was established as a Double of the Second Class by Pope John XXII to celebrate the Trinity. It was raised to the dignity of a Double of the First Class by Pope Pius X on 24 July 1911.
In the traditional Divine Office, the Athanasian Creed (Quicumque vult) is said on this day at Prime. Before 1960, it was said on all Sundays after Epiphany and Pentecost which do not fall within Octaves or on which a feast of Double rank or higher was celebrated or commemorated, as well as on Trinity Sunday. The 1960 reforms reduced it to once a year, on this Sunday.
Almighty God,in making know to us that His one devine Nature is possessed by three distinct Persons reveals to us something of His own interior life.
Thus the Son possesses this life because the Father gives it to Him by an act of Knowledge which preseeds from the divine Intelligence, and the Holy Ghost, because it is communicated to Himby the Father and the Son, by an act of love having it origin in the Will.
And the divine mercy shines forth in the fact that we are called to share this happiness, which is proper to God alone, by knowing and lovingHim as He knows and loves himself.
