Today, we celebrate the Solemnity of the Most Holy Trinity. This will probably be the most theologically technical bulletin I have ever written. I won’t write like this often, but I think it is a worthy endeavor to attempt to explain the Trinity which is conceptually very difficult to understand. Humorously, priests dread preaching Trinity Sunday. In fact, the course on the Trinity in seminary has a notorious reputation for being extremely difficult. Many people who have trouble understanding it make the mistake that Catholics believe in three distinct gods. We do not! We believe in one God in three persons - unity in diversity and diversity in unity.
The Trinity is the mystery of God’s inner life. By mystery, we do not mean that we cannot know anything about God’s inner life. On the contrary. We come to know about God’s inner life through Divine Revelation, what we, as Catholics, come to understand as both Scripture and Tradition. We know that God is Triune because God has spoken through his humanity and he has told us so.
There are five words that have to be properly understood in order to understand the Trinity:
Nature (essence)
Relation
Procession
Generation
Spiration
In Catholic theology, we understand the three persons of the Trinity to be distinct relationally but not in nature (essence). So, we can say that the Father is not the Son; the Son is not the Father; neither the Father nor the Son are the Holy Spirit and vice versa. We can say that, though the persons are distinct relationally they share the same nature (essence) - their nature being divine nature as opposed to human nature. We can kind of understand this concept by thinking of humanity. We humans are distinct both relationally (and also physically and spiritually - this is where the analogy falls way short…) but we do share the same nature - human nature. Our nature is distinct from the divine nature of God. We are finite and limited. God is infinite - He is being itself (being qua being as St. Thomas Aquinas writes). In the Nicene Creed that we profess each Sunday at Mass, we use the word “consubstantial” to convey this understanding - with the same substance (or nature/essence).
In understanding the relations and the nature within the inner life of the Triune God, we now have to understand the processions of the persons. The Father eternally generates the Son thereby constituting the person of the Father (in relation to the Son). The Son is generated by the Father thereby constituting the person of the Son (in relation to the Father). To understand this generative procession we use the word ‘begotten’ in the Nicene Creed. The ‘begetting’ of the Son is an intellectual ‘begetting’ meaning there are not two distinct beings involved (as a mother and a father would beget a child). Rather, in Scripture we understand the Son to proceed from the Father as the Word (made flesh) (John 1:14). To help us understand this procession, when I speak a word, that word proceeds from me into being while at the same time remaining within me (within my intellect) as the one who spoke it. The Holy Spirit, on the other hand, proceeds from the Father and the Son, not in a generative way, but rather through what St. Thomas Aquinas calls spiration. Spiration comes from the Latin word spiritus meaning ‘spirit’ or ‘breath.’ “And when he said this be breathed on them and said to them, ‘Receive the Holy Spirit’” (John 20:22). We can think of the Holy Spirit’s procession not as an intellectual procession but rather like a procession from the will. Through Divine Revelation, we understand the Holy Spirit to pertain to the love between the persons of the Father and the Son - love being the ultimate act of the will. We read in St. Paul’s letter to the Romans, “...the love of God has been poured out into our hearts through the Holy Spirit that has been given to us” (Romans 5:5). Properly understood, love as a virtue is willing the good of the other. The love between the Father and the Son is so perfect that it eternally “breathes forth” (spirates) the third person of the Trinity - the Holy Spirit.
The Trinity, properly understood, can be summed up in one word - love. In Christianity, we understand God to be love itself. In order for God to be love itself, there must be another person to be loved. There must be a beloved. For all eternity the Father, Son, and Holy Spirit have lived this eternal relationship of love within themselves. Being made in God’s image and likeness (Genesis 1:27), we understand then that we are made for relationship; we are made for love. The Triune God invites each of us to participate and get caught up in His divine nature and experience His love through the liturgy, the sacraments, the spiritual and corporal works of mercy, in our personal and collective prayer, and even in our own penances and sacrifices.
Sometimes we just have to bow to the mystery of God knowing that we will not fully understand everything about eternity and infinity in this finite and limited life. One day we will!