The Solemnity of the Most Holy Trinity that we will celebrate this coming Sunday honors not an event, but a truth revealed by Jesus Christ – and according to the Catholic faith, it is the most important truth of all. Trinity Sunday, which falls on the Church calendar one week after Pentecost, celebrates the eternal life of God, who is one and yet is three divine persons.
Before he ascended to heavenly glory, Jesus told his disciples to go and “make disciples of all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Spirit” (Matthew 28:19). Observing what the Lord commanded, the Church has from the beginning worshiped the one God as a loving communion of three divine persons in undivided unity.
In the second century, we find a special word for this profound mystery emerging – Trias in Greek, and Trinitas in Latin, both translated into English as Trinity. Many of the early prayers and liturgies of the ancient Church, include this trinitarian focus and in the most ancient professions of faith, we also find a belief in the Trinity of the Father, the Son and the Holy Spirit.
It seems so natural to celebrate the Trinity that many centuries ago, some theologians argued that a feast would be redundant. Every Sunday, they said, was “Trinity Sunday” because the Mass is fundamentally a trinitarian prayer. Yet many local churches went ahead anyway and celebrated a special day in honor of the triune God. Almost seven centuries ago, in 1334, Pope John XXII established Trinity Sunday as a feast for the entire Latin Church.
For Catholics today, the Holy Trinity remains a focus of our private daily prayer and our public worship at Mass. When we make the sign of the cross, we pray “in the name of the Father, and of the Son, and of the Holy Spirit.” The sign of the cross is the most familiar and concise summary of our Catholic faith. When we baptize, we do so with the same trinitarian formula, as Jesus directed. The Congregation for Divine Worship, in its directory on the liturgy, says this signifies that the baptized begin a life of intimacy with God, “as sons of the Father, brothers of Jesus and temples of the Holy Spirit.”
Throughout Mass, we recite our belief in the Trinity. We pray in the Gloria, “. . . You alone are the Most High, Jesus Christ, with the Holy Spirit, in the glory of God the Father.” We also profess in the Creed, “I believe in the Holy Spirit, the Lord, the giver of life, who proceeds from the Father and the Son, who with the Father and the Son is adored and glorified…” In the doxology of the Eucharistic Prayer, the celebrant prays, “Through him, and with him and in him, O God, almighty Father, in the unity of the Holy Spirit . . .”
The Catechism of the Catholic Church underscores the importance of this teaching when it notes: “The mystery of the Most Holy Trinity is the central mystery of the Christian faith and of Christian life” (CCC 261). The Trinity is the truth at the foundation of all other truth. This mystery exceeds human understanding, but it is a truth we come to know through faith.
God the Father revealed the Trinity by sending the Son into the world to bestow the Spirit. Before his death, Jesus announced the sending of the Holy Spirit, who from the beginning was with God and who will now dwell as God with us after Jesus’ death, resurrection and ascension in glory.
In Baptism, we are called to share in the life of the Blessed Trinity in such a way that the one God in three persons actually comes to dwell within us. We celebrate the Trinity and the power of God’s grace in us every time we sign ourselves in the name of the Father, and of the Son, and of the Holy Spirit, a belief we affirm by then saying, “Amen.”