By Elizabeth Klein
Assistant Professor of Theology at the Augustine Institute
If you are a lifelong Catholic or if you have taken theology classes at some point in your life, you are probably familiar with what the Church teaches about God: that God is Trinity, one God in three persons. You have likely made the Sign of the Cross and heard the words, “In the name of the Father, and of the Son and of the Holy Spirit” thousands of times. Unfortunately, this familiarity with the Trinity is about as far as most Catholics have gone in contemplating God. By contrast, the Catechism of the Catholic Church says that:
“The mystery of the Most Holy Trinity is the central mystery of Christian faith and life. It is the mystery of God in himself. It is therefore the source of all the other mysteries of faith, the light that enlightens them. It is the most fundamental and essential teaching in the ‘hierarchy of the truths of faith’” (CCC 234).
What a strong endorsement from mother Church to push us to understand the Trinity ever more deeply! The Catechism is telling us that the mystery of the Trinity is not only the most important teaching of the Catholic faith (i.e. the most important thing that we can know), but it is also the central mystery of Christian life (i.e. the most important thing for how we live). But how can that be? What difference does it make to my life whether God is one or three or 15?
A good place to start is by looking at what the Church teaches about the Trinity. The doctrine of the Trinity arose from a careful reading of the Bible and from a sustained reflection on who Jesus is. If Jesus claims to be God by forgiving sins (e.g. Mk 2:7, Lk 5:21) and by his unique relationship to the Father (e.g. Jn 10:30), then how can it still be true that there is only one God, also a fundamental truth of the Bible (e.g. Deut 6:4, 1 Cor 8:6)? Would there not be at least two Gods – the Father and the Son — or does the Son have some other status, like a demigod or an angel? These questions drove centuries of discussion in the early Church, and they have brought forth some of the most beautiful theological writings about the nature of God and the person of Christ. That is why the Catechism says that the Trinity is the fundamental teaching of the faith, because it is the answer to the primary question of all of theology: who is God? If we cannot answer that question, or at least begin to answer it, the rest of the faith would be emptied of its meaning, since our whole faith is about relationship with God (and through God, with our neighbor). If we get God wrong, we get religion wrong and we can end up worshipping a false image of God that we have in our mind, which is ultimately idolatry.
What the Church came to see through wrestling with the scriptures and with the events of Jesus’ life is that somehow, although God is one, God is not solitary. God is a communion of persons — Father, Son and Holy Spirit — only one God, having only one divine nature, but existing in three persons who can be named, not because they are three separate somethings, but because they are three distinct someones. This revelation about God is no small matter. It means that God in himself is relational. It means that, as St. John puts it, “God is love” (1 Jn 4:8). St. Augustine therefore explains the Trinity in this way: if you see love, you see the three — the one who loves (the Father), the one who is loved (the Son) and the love itself (the Holy Spirit). Love cannot exist in the abstract; you cannot say “I love” without saying what or whom you love; so likewise, God’s love is of and for something, except that God is entirely self-sufficient. What he loves is himself, and in that love, there is both perfect unity and perfect relationship.
Now we can begin to see why the Catechism speaks of this mystery as central not only to our faith but also to our life. When you love aright, you do so by means of God, who is love; just what kind of love is revealed by Jesus Christ, and we can read about it in the gospels. Jesus also invites us to share in this same love, to be his friends (Jn 15:15) and to join his fellowship (1 Jn 1:3). God, therefore, is the end goal of our love, the means by which we love, and has provided an example of how to love. God, in himself, is the only true version of what is so often referred to as “unconditional love,” because only the Trinity loves wholly, perfectly, without reservation and without ulterior motives. It is precisely this love which God offers to us in Christ, because Christ is not simply a messenger or an angel, but he himself is God, the very incarnation of love.
To put it succinctly, the Trinity is the central mystery of Christian life because love — or charity — is both the goal and the means of the entire Christian life. After all, what we want most, even on a purely human level, is to love and be loved, to know and be known. We want to have perfect harmony within ourselves and with everyone else — be they friends, family, coworkers or strangers — without losing who we are uniquely. We want to love our spouse with all that we have, and we want them to love us for who we are too. Virtually every love song gives voice to this desire in one form or another. And so, as it turns out, what we want (perfect unity and perfect relationship) is who God is, even as we recognize that human friendships are an incomplete reflection of the Triune life of God.
But what is perhaps most amazing of all about the doctrine of the Trinity is that it is, properly speaking, none of our business. From the “outside” we would never know this fact about God, since it is only from the “inside” — within God’s inner life — that we can know how the three persons are distinct in their relationship to one another. It is, as the Catechism says, “God’s innermost secret” (CCC 221), a secret that we are meant to share for all eternity, a secret that God hinted at in the Old Testament, and a secret that he has shared with us fully by the sending of the Son. And when a good friend or loved one tells us an intimate secret, it would be extremely rude to yawn, to be inattentive or to change the subject — reactions, I fear, that are all too common when it comes to the profound mystery of the Trinity.
Featured art: Holy Trinity fresco from Altlerchenfelder church