Trinity Sunday
Dominica Sanctissimae Trinitatis
Trinity Sunday is the solemn feast of the Most Holy Trinity, on which the Church adores the one God in three Persons — Father, Son, and Holy Ghost — kept on the first Sunday after Pentecost.
On the Sunday after Pentecost the Church pauses to adore, in one great act of worship, the central mystery of the Christian faith: that God is one in nature and three in Person — Father, Son, and Holy Ghost. Having celebrated through the year the works of our salvation — the coming of the Son at Christmas, his Passion and Resurrection at Easter, the descent of the Holy Ghost at Pentecost — the Church now turns to contemplate the one God who wrought them all, blessed and undivided in his eternal life.
The mystery we adore
The doctrine of the Holy Trinity is not the conclusion of human reasoning but a truth revealed by God himself. The Lord Jesus made it known when he sent his Apostles to baptise “in the name of the Father, and of the Son, and of the Holy Ghost” — one Name, for one God; three Persons, truly distinct yet equal in majesty, eternity, and power. The Father is God, the Son is God, the Holy Ghost is God, and yet there are not three Gods but one God. This the Church confesses each Sunday in the Creed, and on this feast she lifts up that confession as her highest praise.
The Church does not pretend to comprehend what God has revealed; she believes it, adores it, and rejoices in it. The mystery of the Trinity is not a riddle to be solved but a life to be entered, for by Baptism the faithful are made sharers in the very life of the three divine Persons, and are called at last to behold them face to face in glory.
How the feast came to be
Devotion to the Holy Trinity is as old as the faith itself, woven into every blessing, every doxology, and every sign of the Cross. A particular Mass in honour of the Trinity was composed in the early Middle Ages, and the feast spread widely through the Western Church. In the year 1334 Pope John XXII extended its observance to the whole Latin Church and fixed it upon the Sunday after Pentecost, where it has remained ever since as a feast of the first class.
The placing of the feast is itself a kind of teaching: only when the whole work of redemption has been unfolded, and the Holy Ghost has been poured out upon the Church, does she gather all her praise into the adoration of the one God who is its source and its end. The collect of the day thanks God for having given his servants, in the confession of the true faith, to acknowledge the glory of the eternal Trinity and to worship the Unity in the power of his majesty.
The Collect
Almighty and everlasting God, who hast granted to thy servants, in the confession of the true faith, to acknowledge the glory of the eternal Trinity, and in the power of thy majesty to adore the Unity: we beseech thee, that by steadfastness in this same faith we may evermore be defended from all adversities.
Omnípotens sempitérne Deus, qui dedisti fámulis tuis in confessióne veræ fídei, ætérnæ Trinitátis glóriam agnóscere, et in poténtia majestátis adoráre Unitátem: quæsumus; ut, ejúsdem fídei firmitáte, ab ómnibus semper muniámur advérsis.
Patronage
The feast is dedicated to the adoration of the Most Holy Trinity, the central mystery of the Christian faith and the source of all blessing.
In the Modern Calendar
In the modern calendar this feast is likewise observed on the Sunday after Pentecost, under the title of the Most Holy Trinity, ranked as a solemnity.
Common Questions
When is Trinity Sunday?
Trinity Sunday is a movable feast kept on the first Sunday after Pentecost, eight days after Pentecost itself. Because Pentecost depends on the date of Easter, the date of Trinity Sunday changes from year to year.
What does Trinity Sunday celebrate?
It celebrates the mystery of the Most Holy Trinity — that there is one God in three divine Persons: the Father, the Son, and the Holy Ghost, equal in glory and majesty. It is the central mystery of the Christian faith, revealed by Christ himself.
Why is it kept right after Pentecost?
Through the year the Church celebrates the works of salvation accomplished by the three divine Persons, ending with the descent of the Holy Ghost at Pentecost. Trinity Sunday then gathers all that praise together, turning from the works of God to adore the one God who is their author. Pope John XXII extended the feast to the whole Church in 1334.
See where this feast falls in the Church’s year on the liturgical calendar, or find a Traditional Latin Mass near you.
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