"Batter my heart three-person God"
--John Donne, "Meditation 14"
Preaching on theological-theme-Sundays is particularly challenging because it invites abstraction and can quickly turn into a lecture; even in a seminary, seminary professors want to hear a homily and not a lecture at Mass.
The Holy Trinity is difficult because the official declaration of God's identity as "three persons one God" seems to run contrary to our understanding of what it means to be a person. For many, such language brings up popular images of "multiple personalities" in a single person suffering from a mental disorder. There is a quotation from the spiritual masterpiece The Imitation of Christ by Thomas a Kempis that gives us a great place to start:
"What good does it do to speak learnedly about the Trinity if, lacking humility, you displease the Trinity? Indeed, it is not learning that makes a man holy and just, but a virtuous life makes him pleasing to God. I would rather feel contrition than know how to define it." Book 1, Chapter 1
The first thing we should recognize is that any theological understanding finds its ultimate meaning in the goal of all Christian life: to allow God to transform us daily into becoming more the Christ that has dwelled in us since baptism. With that in mind (and heart), let's consider today's readings, how the blessed Trinity is revealed in them and the implications for our life in Christ.
One of the essential characteristics of the Trinity is relationship, and God's "aseity", or uncreated, perfectly actualized being. Wow, that sounded like the beginnings of a seminary essay! Scripture implies not only God's uncreated nature, it also gives us an experience of God as moving away from self into humanity in the form of revelations (the Prophets) and redemptive action (Jesus as Christ), and acting within human nature in such a way to recognize in oneself, and one's neighbor, the Divine. This three-part structure: God-self, God-revelation, God-within humanity becomes the basis to reflect our experience of God's relationship to humanity.
Deuteronomy speaks of God's existence in both heaven and earth, acting in both revelation and redemption.
...fix in your heart, that the LORD is God in the heavens above and on the earth below, and that there is no other . . . . that you and your children after you may prosper, and that you may have a long life on the land . . . ."
In Paul's letter to the Romans, he explicitly writes of God in terms of Father, Spirit and of being "heirs of God and joint-heirs with Christ"
The text takes an interesting turn, then, and suggests that this relationship is only fully recognized (The Spirit himself bears witness with our spirit) "if only we suffer with him". Paul is suggesting that we will be led by the Spirit into the sufferings of Christ to enter into the glory of the Father. How often do we regard God as aloof and incapable of suffering because of the attribution of "perfect". Something perfect does not suffer, but God as the Christ did suffer (contrary to the rather insipid claim of the Gnostics) and does suffer. The reason God suffers, for Paul, is clear: we are all God's children. God suffers because of His great love of his creation and his perfect love expressed in our free will to walk away from our inheritance like a petulant child walks away from Disneyland to play in the backyard on a dry, brown lawn with broken toys in the summer heat to spite his parents.
In Matthew's gospel, the Trinity is explicit in the triadic baptismal formula with the promise that the role of the disciple is to teach the world "all that I have commanded you". If you remember three weeks ago, Jesus commands his disciples: "love one another". The mission, then, of both the Church and the individual, is one of "going out" into the world, as Christ and the Father "went out" of themselves---God in creation, revelation, and redemption, Christ in perfect obedience to the Father. This centrifugal force of the Spirit, though, is only possible as a fruit of loving one another--the centripetal force of the inwardness of God's presence within us and Christ's presence in the community of the faithful. What draws us together, leads us to the mission.
The mission will "batter" us, to quote the epigraph from Donne, but we live because we are embraced by God's Spirit in following the battered Christ resurrected. Donne's pleading seems masochistic until one realizes that to join in this family of God's children, the way of life and glory is also the way of suffering and death for love of the other, embodying the practice of the Trinity. Who could ever understand such love?