The Solemnity of the Most Holy Trinity – Year A
Today we celebrate the Solemnity of the Most Holy Trinity. The Catechism tells us that “the mystery of the Most Holy Trinity is the central mystery of Christian faith and life”: in other words, out of all the many mysteries that we are called to believe and love, like the mystery of the Incarnation, the mystery of the Eucharist, of all the mysteries that there are, this one, the mystery of the Trinity, that there is one God in Three Persons, is at the heart and center of our faith. In fact, the Catechism continues by telling us that the Mystery of the Trinity “is . . . the source of all the other mysteries of faith; [it is] 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.”
In other words, the whole history of salvation, everything that God has done from the dawn of time, through Adam and Eve, through the Old Testament, up to the birth, life, death, and resurrection of Christ, up until our day, is nothing more than the Trinity revealing Himself to us, and bringing us back to Him.
To understanding this better, we can consider, first, this gradual revelation of the Trinity as seen in today’s readings and, second, what this means for our lives.
In today’s first reading, Moses goes up to the mountain, and God passes by, declaring His mercy and love. As a reply, Moses worships God, and asks Him to “come along” with His people, to be with them and aid them in their needs. As a loving Father, God will accompany His people, in the midst of difficulties, trials, and infidelities.
It’s true that “many religions invoke God as ‘Father.’” Usually, though, this just refers to the fact that God created the world. In Israel, God is called ‘Father’ not only because He created everything, but also because He lovingly established a covenant and gave gifts to Israel, and His loving protection of the poor, widows and orphans, and the defenseless.” At one and the same time, God is both the first origin of everything and of all authority, and also goodness and loving care for all His children.
Yet, God the Father doesn’t stop there; He reveals Himself fully through His Son, Jesus Christ. “Jesus revealed that God is Father in an unheard-of sense: he is Father not only in being Creator; He is eternally Father in relation to His only Son, who is eternally Son only in relation to His Father. Jesus is ‘the image of the invisible God,’ the ‘radiance of the glory of God and the very stamp of his nature.’”
This is so important because by revealing that God is our Father, He at the same time teaches us who we are (children!). Saint Ambrose puts it this way: “O man, you did not dare to raise your face to heaven, you lowered your eyes to the earth, and suddenly you have received the grace of Christ all your sins have been forgiven. From being a wicked servant you have become a good son.” We are God’s beloved children, and the second reading, from Saint Paul’s second letter to the Corinthians, reminds us that we are all brothers and sisters precisely because we are all adopted children of God. The ending of the reading, a Trinitarian blessing, “The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with all of you,” reminds us that the work of the Trinity is to reveal itself to the world, and to reveal itself to us in a particular way through our sanctification and salvation: “Mend your ways, encourage one another, agree with one another, live in peace, and the God of love and peace will be with you.”
What is our response to this? As we said earlier, the Trinity is the great mystery of our faith, and we must love it and pray about it, trying to have it penetrate every aspect of our lives. We need to live a Trinitarian faith.
What does that mean? We need to consider how we live out our belief in each of the three Persons of the Trinity. Usually people have the easiest time with the Second Person, Jesus Christ, since He assumed a human nature and lived among us. But, still, we can ask ourselves about how well we consider His presence among us, especially in the Eucharist and in the Mass.
What is our faith in the Father like? Is God really a “father” for me? Do I have difficulties in talking to God as my Father? Do my words in prayer reflect the tenderness of a child? What is my awareness of being a child of God? What is my closeness and my confidence with God the Father? Are my dealings very personal, trusting, friendly, open, like a child with their earthly father? Do I really think that Jesus Christ reveals the Father, that Christ is an image of God the Father’s paternal love and affection for me?
Lastly, what is our faith in the Holy Spirit like? Do I ask for His help and guidance in difficult moments? Am I aware that He is my ever-present companion, who seeks to help me in all my struggles and to give me the graces that I need to continue moving forward on the path to holiness?
Today, through the intercession of Mary, the Delight of the Trinity, let us ask for the grace to continually grow in our love for and understanding of the Trinity, a mystery that we can never fully understand, but even a little knowledge of which brings us to the heart of God.
 CCC, 234.
 Cf. CCC, 238, 239.
 Cf. CCC, 240, 241.