Each year, the Church commemorates the mysteries of our salvation, from Christ’s birth in Bethlehem, to His death and resurrection, to the coming of the Holy Spirit at Pentecost. This week, the liturgy invites us to contemplate the central mystery of our faith: the Blessed Trinity, the mystery of God’s own inner life and the source of all graces and gifts.

In His providence, God gradually revealed to human beings His own nature as a communion of three Divine Persons, sharing one and the same Divine Nature. In the Old Testament He makes known above all His oneness and His complete transcendence from the world as its Creator and Lord. At the same time, the Old Testament proclaims the love and mercy of God, who cares for and forgives His people, who guides and protects them. Furthermore, even in the Old Testament, we get glimpses of the paternity of God the Father, of the Incarnation of God the Son (whose coming is foretold by the prophets), and of the action of God the Holy Spirit, who gives life to all things.

It is Jesus Christ, however, who reveals to us the Trinitarian mystery in all its fullness and calls us to participate in it by grace. Christ speaks intimately of Himself, His Father and the Holy Spirit as equal in power, majesty and divinity. He tells us that He has come to give us life, to give us access to the Father in the unity of the Holy Spirit. Christ invites us to seek above all things communion with the Holy Trinity, in whose presence we hope to live forever.

The mystery of the Trinity — which we could never know by ourselves — is the starting point of all revealed truth, the fountain from which all supernatural life flows, and the goal to which every human person is ordered. The contemplation of God’s inner life sheds light on our own dignity: we are children of the Father, brothers and sisters of Jesus Christ and co-heirs with the Son, and we are continually sanctified by the Holy Spirit to make us resemble Christ more and more.

The Blessed Trinity, therefore, is not just an abstract theological truth. Instead, it lies at the very center of our faith, and it is a mystery that we invoke constantly. Whenever we make the sign of the cross, we profess our belief in the Trinity. We were baptized in the name of the Father, the Son, and the Holy Spirit; and in their name also our sins are forgiven. The prayers of the Mass are directed to the Holy Trinity, and our personal prayers, though we may address only one of the Divine Persons, are heard and answered by all three.

Pope John Paul has reminded us that the whole of the Christian life is like a great pilgrimage to the house of the Father. On this pilgrimage, we are accompanied each day by the Holy Spirit, who makes Christ present to us and keeps us mindful of His saving words and deeds. The Trinity is the beginning and the end of our entire existence, for God imparts to us a share in His own life and love, and calls us to communion with Himself. With grateful hearts, especially on this Trinity Sunday, let us acknowledge and reverence the God whom we adore: "Glory be to the Father, and to the Son, and to the Holy Spirit. As it was in the beginning, is now, and will be forever, world without end. Amen."