Why do we celebrate the Blessed Trinity?
Doesn’t the Mass always honor the Trinity?
In the Church’s early days, she did not have a specific feast for the Blessed Trinity. The Trinity was honored through certain prayers in the Mass—the Gloria especially focuses on this fundamental Mystery, praising and adoring our Triune God—but there was not yet a dedicated feast day.
For years, the Church remained content with this quiet daily way of honoring the Blessed Trinity. However, when the heresy of Arianism came on the scene, she knew that it was necessary to loudly and decisively proclaim belief in the Blessed Trinity.
Arianism rejected the Church’s central dogma of the Blessed Trinity, claiming that Jesus Christ was not truly divine. Jesus, the heresy said, was created by God as a sort of secondary god, clothed with divinity but not eternal and uncreated. This secondary god’s role was to create and redeem the world.
To stem the Arian heresy, the Church Fathers wrote a special Office for the Blessed Trinity to be prayed on Sundays. In this way, the Church honored the Trinity for several centuries. Then, in the 14th century, Pope John XXII declared a universal, annual Feast of the Blessed Trinity and set it on the Sunday after Pentecost.
The Church chose this Sunday in order to reflect the honor we pay to the Blessed Trinity throughout the liturgical year.
At Easter we celebrate Jesus Christ, Who shows us the Father. At Pentecost, the Holy Spirit receives particular honor as He comes to the Apostles and enables them to preach the Gospel. The Holy Spirit’s coming marks the beginning of the Apostles’ mission to the world. They now fulfill Christ’s last command to them: to baptize every nation in the name of the Father, and of the Son, and of the Holy Spirit—the Blessed Trinity.
Acquired from: https://www.catholiccompany.com/getfed