Belief in a triune God is fundamental to the life of every Christian, not simply a topic for theological speculation. We begin every liturgy invoking the name of the Trinity and are sent forth with a blessing from Father, Son and Spirit. God as three persons, shapes every aspect of our faith from liturgy to concerns about social justice. The deepest meaning of the Trinity rooted in Scripture is not God beyond us, but in the words of the late Catherine Mowry LaCugna God for Us. Simply put, the Trinity expresses the essential truth that the God who saves through Christ by the power of the Spirit lives eternally in the community of persons in love. (This is from the article Trinitarian Spirituality in the Collegeville Dictionary of Spirituality, by C. M. LaCugna and M. Downey, which I highly recommend.)
Today’s readings, which speak of the salvation accomplished through Christ and its effects, capture this insight beautifully. Romans 5 begins a major turning point in the letter. After a bleak picture of the human condition without God and a profound reflection on the need for God’s grace by both Jew and gentile, Paul begins a new section on the effects of God’s free gift of salvation and justification in Jesus. Here, as in other places, he joins the action of Father, Son and Spirit. We have peace, that is, the wholeness of a restored relation with God, and we stand in God’s grace that gives us hope amid all difficulties. Paul hurries to the result, the love of God [that is, the love God has for us] has been poured out into our hearts through the Holy Spirit. Pouring evokes the life-giving water of Isa. 44:3, Fear not, O Jacob, my servant, the darling whom I have chosen. I will pour out water upon the thirsty ground.
The Gospel presents a section of Jesus’ farewell discourse, in which he promises that the Spirit of truth will come to guide the disciples to all truth (truth in the sense of unveiling or revelation, rather than verification). In John, the Spirit of truth promised after Jesus’ departure is also called paraclete (advocate or counselor) as well as Holy Spirit. The Spirit will effect in the lifetime of the community of disciples what Jesus did during his earthly ministry: guide them into truth, defend them in time of trial and glorify, that is, make present the incarnate Word.
I fear these reflections commit the fault I referred to earliermaking the Trinity more obscure. Yet the feast celebrates the nature of God existing for us and revealed to us. God is a creative and loving parent who pours out love by taking on the human condition even unto death and continues to live in our midst by forming a community of beloved disciples, which lives in imitation of the koinonia or intimate community of the divine persons and expresses this in love for others. We begin and end our liturgy invoking the triune God, as a symbol and mandate for a manner of life.