What is the Trinity?
It has been said that if the mind were simple enough for us to understand it, we would be too simple to understand it. Likewise, if God were simple enough for my finite, fallen mind to understand him, he would not be God. How does a mother explain marriage to her five year old daughter? How does a mathematician explain calculus to his third grade son?
Yet we try. We sing as though we understood the words, “Holy, Holy, Holy! Lord God Almighty…God in three Persons, blessed Trinity.” I speak the same words over new believers which were recited over me in the baptismal waters, and over other Christians for twenty centuries: “I baptize you in the name of the Father, and of the Son, and of the Holy Spirit.” Why? What is the Trinity? And why is understanding it so essential?
A brief history of God
The first biblical reference to God starts the mystery: “In the beginning God created the heavens and the earth” (Genesis 1:1). The Hebrew term here translated “God” is Elohim. The “im” is how the Hebrew language makes a word plural, like putting “s” on the end of a word in English. Thus one could translate the word “Gods” (though some Hebrew scholars believe that the plurality points more to God’s majesty than his number).
However, the following Hebrew verb “created” requires a singular noun, indicating that its subject is one rather than many. In English we would say “they create” but “he creates”; the latter is the idea of Genesis 1:1. So, in “God created” we have our start into the mystery that is the nature of God.
From earliest times, the Jewish tradition has affirmed that “the Lord our God, the Lord is one” (Deuteronomy 6:4, the “Shema” which is recited in daily Jewish spirituality). Such monotheism was a radical departure from the polytheism of ancient cultures. But the experience of the first Christians made simple monotheism problematic, for they knew Jesus Christ to be Lord and God (cf. John 1:1; 20:28; Romans 9:5; Titus 2:13). They also experienced the Holy Spirit as divine (Genesis 1:2; cf. Acts 5:2, 4; 2 Corinthians 3:17-18). But these three were independent (at Jesus’ baptism the Father spoke and the Spirit descended; Matthew 3:16-17).
There is no indication that apostolic Christians struggled with the logic of their experience of God. Paul could pray for the Corinthians, “May the grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit, be with you all” (2 Corinthians 13:14). They knew God to be one, but they experienced him as three persons. This logical contradiction did not trouble them, for they were more pragmatic than speculative. They needed no words such as “Trinity” or theological formulations to explain their faith. But matters would quickly change.
The problem of God
As Christianity spread beyond its Jewish roots, it encountered a worldview steeped in logic and rationalism. Aristotle had taught the Western world that non-contradiction is the test for all truth. Something cannot be one and three at the same time. So how can the Christian doctrine of God be reasonable?
The earliest answers to the question resolved the logical tension, but created problems greater than the one they “solved.” Some made the Son and the Spirit less divine than the Father, an approach known as subordinationism.” By this formulation, Jesus is not Lord and the Holy Spirit who makes us Christians (cf. Romans 8:9) is not fully God. Others taught that God shifts from being Father (Old Testament) to Son (Gospels) to Spirit (Acts to Revelation), an approach known as “modalism.” This strategy cannot explain the baptism of Jesus, the work of the Son (John 1:3-4) and the Spirit (Genesis 1:2) in creation, or the presence of the Spirit throughout the Old Testament (cf. Psalms 51:11).
At the Councils of Nicaea (AD 325) and Constantinople (AD 381), the orthodox Church declared all such formulations to be heretical, and affirmed that the Son and Spirit are of the same “essence” as the Father. “God in three Persons” catches the sense of their approach.
From then to now, believers have sought to understand better this paradox. Some suggest that God is like water, capable of being solid ice, liquid, or steam (but not at the same time). Perhaps he is like a three-sided pyramid seen from above (but the three sides do not work independently as did the Trinity at Jesus’ baptism). Maybe he is like an egg: yoke, sac, shell (but the three do not retain the same essence). Perhaps he is like a woman who is mother to her children, wife to her husband, and daughter to her parents (but she cannot act in three independent ways at the same time). All analogies eventually break down, as they should. As we noted earlier, if we can understand fully the essence of God, he would not be God.
Commitment to a God whose essence transcends our logical comprehension is a problem for some in our rationalistic culture. We like our faith to make sense. We may not understand why a ship floats or an airplane stays in the air, but we know that someone does. We’d have a hard time taking medicine no one understands, expecting effects no one can explain.
But we’d best get used to it. The more we learn about the universe, the more incomprehensible it becomes. Physicians do not understand how the mind works, or even if there is such a thing as the “mind.” We assume the category of time, but none of us can define it without contradiction.
So it is with the major doctrines of Christian faith. Is God three or one? Is Jesus fully God or fully human? Does God know the future or do we have freedom? Is the Bible divinely inspired or humanly written? The answer to each question is the same: yes.