Given the current situation in the United States, I think it's perfectly fitting to begin my reflection on the readings for the Solemnity of the Most Holy Trinity by pointing out that God himself is unity in diversity. While we can play God's diversity off against divine unity, it is important to be full-blown Trinitarians, as opposed to mere monotheists. Among the so-called Abrahamic faiths (Judaism, Christianity, and Islam) understanding God as Triune makes Christianity distinct. This is important because the Blessed Trinity provides a model for our relationships.
Rather than beginning from some abstraction, by explaining how "three" and "one" can be applied to the same object, namely a "thing" we call "God," any meaningful grasp of the Most Holy Trinity with Jesus Christ, in whom "dwells the whole fullness of the deity bodily" (Colossians 2:9). It is Jesus who fully reveals God as Father, who teaches his disciples to pray, "Our Father..." Coming fresh off Pentecost, we know that it is Christ who sends the Holy Spirit to be the mode of his resurrection presence among us, in us, and through us until his return. It is by the Holy Spirit that the bread and wine become Christ's Body & Blood, by our reception of which we become Christ's Body.
In one of the great works of twentieth-century Catholic theology, Corpus Mysticum, the great Jesuit theologian Henri DeLubac noted that over centuries the Church's understanding of verum corpus (i.e., "real," or "true body") and corpus mysticum (i.e., mystical body) were switched up. We still suffer the effects of this reversal. Formerly, the consecrated species (i.e., the bread and wine) were understood to be Christ's "mystical body," while the Church, in all her members, was reckoned to be Christ's "true body" in and for the world.
The idea of making many into one and that all things have a single origin and end pre-date Christianity. Heraclitus, one of the pre-Socratic Greek philosophers, observed in his Tenth Fragment: "The one is made up of all things, and all things issue from the one." The motto of the United States of America is E pluribus unum, which translates as "out of the many, one." We have seen these past few weeks, in the aftermath of George Floyd's death, how difficult this is to bring about.
Later in Saint John's Gospel than our reading for this Trinity Sunday, in his High Priestly Prayer, Jesus prays that all who come to faith in him may be one as he is one with Father (John 17:22-23). This oneness is brought about by the Holy Spirit in a dizzying array of way, but most explcitly through the sacraments, particularly the Eucharist.
Our reception of Holy Communion makes us together Christ's true body. This is why we insist "the Eucharist makes the Church and the Church makes the Eucharist." It is as members of Christ's Body we are sent forth in his name to make God's reign present wherever we are. This is our mission, this is what makes the Church apostolic. This is what the poem, usually erroneously attributed to Saint Teresa of Avila, points to:
Christ has no body now but yours,
No hands, no feet on earth but yours,
Yours are the eyes with which he looks
compassion on this world.
Christ has no body now on earth but yours
As our Gospel for today indicates: God is love (1 John 4:8.16). God's love is not an abstraction. God's love became very real when, by the power of the Holy Spirit, the Son, the Second Person of the Most Holy Trinity, became incarnate in the womb of the Blessed Virgin Mary. God's love became manifest when Jesus was lifted up on the cross. By enduring the cross, the Lord sought to break the cycle of violence, so prevalent in the world. By his cross, Jesus Christ put an end to the enmity, the hate, that so often characterizes human relations in our fallen world. This is clearly explained in the Letter to the Ephesians:
For he is our peace, he who made both one and broke down the dividing wall of enmity, through his flesh, abolishing the law with its commandments and legal claims, that he might create in himself one new person in place of the two, thus establishing peace, and might reconcile both with God, in one body, through the cross, putting that enmity to death by it. He came and preached peace to you who were far off and peace to those who were near, for through him we both have access in one Spirit to the Father (Ephesians 2:14-18)In our second reading, Saint Paul provides a very practical look at what living in communion means. But he begins with by calling the Christians of ancient Corinth to repent by writing, "Mend your ways" (2 Corinthians 13:11).
When it comes to living in harmony together, to bearing witness to Christ by our common life, do we need to mend our ways? When I consider how much acrimony exists in the Church at present, I have you say "Yes, we need to mend our ways." I know I need to mend mine. We need to help one another by forgiving, by exercising forbearance and doing the hard things Jesus calls on us to do. Like Moses prayed on behalf of ancient Israel, we pray: "This is indeed a stiff-necked people; yet pardon our wickedness and sins, and claim us as your own" (Exodus 34:9).
As Christians, rather than master abstractions like the players in Herman Hesse's The Glass Bead Game, let us seek to model all our relationships after that of the Most Holy Trinity. This means seeking to relate to others by means of selfless and self-giving love. It means giving up your worship of the false trinity of me, myself, and I. "Let us ask God to make us true in our love," wrote Saint Elizabeth of the Trinity, "to make us sacrificial beings... sacrifice is only love put into action." This is what it means when Scripture tells us "God so loved the world that he gave his only Son."