The sign of the Christian is the sign of the cross. When we extend our hand to the four directions of our body, we are reminded of the cross and the mystery of our salvation through the suffering of Christ.
While we make that gesture, we are also reminded of another reality through the words, “In the name of the Father and of the Son and of the Holy Spirit.” These words refer to the sublime mystery of the Most Blessed Trinity.
The gospel of today’s Mass shows us the presence of the Blessed Trinity. Jesus Christ, who is God the Son and the second person of the Trinity, talks about the coming of the Holy Spirit, who is the “Spirit of truth” (John 16:13), who is the third person of the Trinity.
Jesus also talked about His Father, the first person of the Trinity, to whom Christ and the Holy Spirit are perfectly united.
The mystery of the Trinity means there is only one God, yet there are three distinct persons in the one God. Each person is God, yet there are not three Gods, but only one. Each person is distinct from the other two, yet they are perfectly united.
It is not a mathematical puzzle or a mere question of semantics. This truth has something to tell us.
While Saint Augustine said: “I am putting the whole sea into this hole,” the saint advised the boy, “Don’t you realize that you can’t fit the whole sea into that little hole?”
And the boy, who must have been a messenger of God, retorted to Augustine, “Well, why then are you trying to fit the vast mystery of God into your limited mind?”
So the first lesson we can derive from this mystery is that of intellectual humility—to realize them the more they act in unison.
In God, knowledge and love are perfect, and the unity is also perfect. Thus, the mystery of the Blessed Trinity reveals to us a rich and fathomless inner activity of God.
God is not like a cold piece of stone on an impersonal force. He is not just a “Master Architect” or “Designer,” as the 18th-century Deists (from which Masonry derives its principles) thought.
God is personal. God is warm. God is full of love and tenderness, not of a sentimental kind but of a realistic and strong kind. This God, who knows and loves Himself through His triple personality, is completely happy in Himself.
Yet, God is so good and His love so great that He has decided to share His happiness with His creatures.
This is where we can understand the great importance of the mystery of Blessed Trinity for our own lives. God has decided to invite each man—you and I—to share that intimate happiness that He has.
That is why we say that we are called to be “children of God” or, as Saint Peter says, we are called to be “sharers in the Divine nature.”
To be Christian is not just a matter of following a set of rules or of observing some external practices. Above all, it means having a certain “life” within us, the very life of God, which is the principle of our actions and convictions as Christians.
This life in us is what Christian doctrine calls “sanctifying grace.” We receive it in baptism (and so we say that through baptism we become children of God and heirs to heaven), and it grows with us through the sacraments and the practice of the Christian life. We lose it through mortal sin, but we can receive it once more through the Sacrament of Penance.
To live a truly Christian life, we must keep within the sphere of the intimate life of God; we must not step out of God’s household.
In other words, we must strive to preserve the state of grace in our souls, so that we become in the Divine Life of the Most Blessed Trinity. That there are realities that are beyond our limited understanding and that we have to accept through Faith.
Yet, Saint Augustine continued to ponder, to seek understanding, without putting his own mind above the faith.
The mystery of the Blessed Trinity also tells us that God is not a distant and impersonal force. God is personal. In God, there is a life of knowledge and love that we can perhaps equate to a very closely-knit family.
God is a father, He has the love and concern of a father. God is a son, He has the piety and respect of a son. God is the spirit of truth and love. And as Saint Peter says, we have been called to participate, to be sharers, in the intimate life of the Blessed Trinity.
It is like an invitation to form part of the “family intimacy” of God. And this takes place through our union and identification with Jesus Christ, who is our brother.
Here we see why the redeeming cross is united to the invocation of the Blessed Trinity, when we make the sign of the cross. It was through the sacrifice of the cross, in which we should all share, that our intimacy with God the Father, the Son and the Holy Spirit, became possible.