Today’s solemnity invites us to contemplate a great mystery: the Trinity. Belief in the triune God has been a defining point of Catholic doctrine for millennia. The Athanasian Creed declares: “we worship one God in Trinity, and Trinity in Unity; neither confounding the Persons, nor dividing the Essence. For there is one Person of the Father; another of the Son; and another of the Holy Ghost.”

Though Trinity Sunday was only raised to a primary feast in 1911, devotion to the Trinity has been observed from Late Antiquity onward in response to early heresies like Arianism. In fact, Sundays have been dedicated to the Trinity long before a feast day was fixed; every time we begin Mass “in the name of the Father, and of the Son, and of the Holy Spirit,” we proclaim this united belief that God is three-in-one.

But what can the reality of the Trinity mean to us personally? St. Paul explains in the Letter to the Romans that we have been “justified by faith” and now have peace with God “through our Lord Jesus Christ.” The faith we have placed in Jesus grants us access to grace, which allows us to “boast in the hope of the glory of God.” This hope is made possible by the Holy Spirit, who pours “the love of God” into our hearts. Because of this work of the Trinity within us, we can even boast of our hardships and afflictions. Each person of the Trinity thus works within us to bring us ever closer to our (one) God and his overflowing love for us. 

In today’s gospel, Jesus assures his disciples that everything the Father has belongs to the Son; it is from this belonging that the Holy Spirit declares “all truth” to those who belong to the Son—thus what we hear from the Holy Spirit comes from God, because the Holy Spirit is God and speaks the truth of God to us. Every time we pray Glory Be, let us give special thanks for the great mystery of the Trinity—one God in three Persons. 

Reflection by Parishioner Kathryn Wilmotte