This Sunday we celebrate the Solemnity of the Most Holy Trinity. “The feast of the Blessed Trinity was introduced in the ninth century and was only inserted in the general calendar of the Church in the fourteenth century by Pope John XXII.”
“The feast of the Most Holy Trinity may well be regarded as the Church’s Te Deum of gratitude over all the blessings of the Christmas and Easter seasons; for this mystery is a synthesis of Christmas, Epiphany, Easter, Ascension and Pentecost.”
We are all familiar with the prayer of “Glory be…by praying this we acknowledge our faith in the Most Blessed Trinity. The words may trip off our lips and we don’t think too deeply about this central tenet of our faith and the foundation of our belief. Thus the Catechism teaches us that this “mystery of the Most Holy Trinity is the central mystery of the Christian faith and of Christian life. God alone can make it known to us by revealing himself as Father, Son and Holy Spirit.” We have the example of Jesus’ Baptism at the River Jordan as a revelation of the Holy Trinity.
The Most Holy Trinity “is the mystery of God in himself. It is therefore the source of all the other mysteries of faith, the light that enlightens them. It is the most fundamental and essential teaching in the “hierarchy of the truths of faith”. The whole history of salvation is identical with the history of the way and the means by which the one true God, Father, Son and Holy Spirit, reveals himself to men “and reconciles and unites with himself those who turn away from sin“.
We are therefore baptised in the name of the Father and of the Son and of the Holy Spirit, “not in their names.”
Now, we do not need to be worried that the Holy Trinity is a difficult concept to understand “we can gain some insight into the Trinity as a model of love.” But “only in heaven shall we properly understand what it means, in union with Christ, to share as sons (and daughters) in the very life of God.” But beforehand we have to consider our relationship to the Father and to the Son and to the Holy Spirit.
Sr. Rosaleen Shaw OP
 Catechism of the Catholic Church #234
 Ibid., #261
 Ibid., #234
 Ibid., #233