The following is adapted from an assignment I submitted in a Christian Theology class with Dr. Jon Huntzinger at The King’s University
1. Epistemology and Revelation
As a young man I considered the evidence for God’s existence and for the truth of orthodox Christian beliefs. Categories of evidence included the testimony of reliable witnesses (such as my parents), historical evidence of God’s involvement in human affairs, biblical testimony, my personal experience, logical reasoning, and the futility and despair I found in alternative ideas. Of these categories, personal experience and biblical testimony have proved the most important, and have formed the foundation of my belief system. But naturally, the testimony of my parents came first.
From my earliest childhood my parents taught me that God is in charge, and that he made everything in the world, including me. These truths have always seemed eminently reasonable to me, to the point that they appear self-evident (Rom 1:19–20). As Calvin wrote, “there exists in the human minds and indeed by natural instinct, some sense of deity.” In this context, I was once overcome by a sense of my own wrongdoing at disobeying my mother, or some such sin. She told me that Jesus would take that feeling away if I asked him, because he died on the cross for what I had done. When I prayed with her, I had such a change on the inside—a lightness and a cleanness and delight—things were made right again and I was free! Ever since then, I have known his voice in my heart. As I grew and began to read the Bible, I recognized that same voice bringing life and light into my world through the words of the Bible. Jonathan Edwards described this experience in 1734 in his sermon, A Divine and Supernatural Light, in which he taught that as we read or hear the Scripture, the Holy Spirit witnesses to its truth, giving us “a real sense and apprehension of the divine excellency of things revealed in the Word of God.”
What I read in the Bible confirmed what my mother and father had taught me, and more. But the starting point was the cross, and it will always be the heart of my knowledge of God. This was also the case for Martin Luther. Prior to Luther, there was an awareness of the centrality of the cross for salvation, and for understanding God the Son, but when it came to Father God, the Greek concept of divine impassibility (that God cannot suffer) clouded the view of many theologians. Aquinas emphasized this supposed attribute of God, which renders meaningless the Gospel truth that God sacrificed his Son out of his love for the world (John 3:16; Rom 5:8). If God cannot suffer, then he cannot suffer pain or anguish over the loss of his Son. But Luther pushes this truth further, arguing that not only did God suffer the absence of his Son in heaven, but that he specifically reveals himself to us in the suffering of Jesus on the cross. He implies that God the Father experienced the agony of the cross along with Jesus. Veli-Matti Kärkkäinen summarizes Jürgen Moltmann’s view, built on Luther’s revelation, that “the cross belongs to the inner life of God.” Moltmann describes the event as a self-contradiction as God was divided from God, but that God was also at one with God through the suffering of the cross, “because God is love.”
2. The Triune Nature of God
When I first encountered the love of God through the cross as a child, I don’t think I had a clear distinction in my mind between God and Jesus. Today my 4-year-old son is the same way. Jesus and God are so alike, and are always talked about together, and they just kind of blend into each other. As I grew, I learned the classical definitions, and how to properly distinguish the different persons of the trinity. But now I believe that the child’s ambiguity is closer to the truth. A number of theologians have reacted against the dominant trend of meticulous definitions of God. Cyril of Jerusalem warned against going beyond what the Scriptures reveal, writing that “it is sufficient for our salvation to know that there is the Father, the Son, and Holy Ghost.” Kärkkäinen paraphrases Karl Rahner’s views, that “rather than inquiring into abstract terms about the inner, hidden life of the Triune God, to which we humans hardly have access, we should turn to the knowledge of Father, Son, and Spirit as provided in revelation and the economy of salvation.” Rahner does seem concerned to understand God’s inner relationships, but believes they are best revealed by observing how he has related to humanity in salvation history.
While I believe that God is One, I also see that each person of the trinity (Father, Son and Holy Spirit) fills different roles in God’s relationship with the universe and with humanity. God the Father is seen enthroned in heaven, and embodies the supremacy, oversight, and loving care of God over all creation (Isa 40:21–28; Ps 104). Richard Bauckham writes that in the Hebrew Scriptures, and other ancient Jewish writings, the revelation of God as he relates to the nations and to the whole created order is as Sovereign and Creator. Bauckham goes on to show how Jesus is identified in the New Testament with both of these characteristics of God, but typically in the Scriptures, and in theology, these traits are associated more with God the Father. For example in Psalm 2, “He who sits in the heavens laughs…” (Ps 2:4 ESV), God is portrayed as sovereign over the rebellious nations, and announces the presence of his Son as king in Zion.
Which brings us to Jesus, God the Son, who is God the missionary, the one who comes to us, who even becomes one of us in order to bring us back to the Father. Asher Intrater, in his book, Who Ate Lunch with Abraham? makes the case that the many appearances of God, or of the Angel of YHVH in the Hebrew Scriptures were this same Son of God who came and through circumcision was brought into the Abrahamic and the Mosaic covenants. He is seen exalted in Ezekiel’s vision of “a likeness with a human appearance” seated on the throne (Ezek 1:26–29 ESV), and in Daniel’s vision of the Son of Man (Dan 7:13–14); he is called God in Psalm 45:6; and yet was willing to humble himself, become a Jew, and bear the shame of all mankind on the cross.
Finally, the Holy Spirit is God, the ever-present one; he is God in us, and God all around us. Yet, again, all of this sounds a bit too clear cut. After all, the Holy Spirit is the Spirit of God. When we talk about a human spirit, we do not consider it a separate person. The spirit of Joseph is Joseph, just a certain aspect of Joseph. The Holy Spirit is also called the Spirit of Jesus (Phil 1:19; Gal 4:6), and how can one spirit belong to two different people? As Michael Brown writes, “God’s tri-unity is not some neatly spelled out doctrine or a trite little teaching to be explained in thirty seconds or less … These are deep theological and philosophical issues.” He goes on to point out that in the book of Revelation John sees God seated on his throne, and the Lamb, representing Jesus is in the center of the throne (Rev 4:2,8; 5:6; 7:9–10,17). Finally, in Revelation 22:3–4, we read, “…The throne of God and of the Lamb shall be in the city, and His servants shall serve Him. They shall see His face, and His name shall be on their foreheads” (TLV). So in the end there is one throne for God and the Lamb, and the singular pronoun is used for him.
3. Reflections of the Trinity in Created Things
Jonathan Edwards writes how many things in the natural world are signs and images of heavenly things. Wheat is a picture of the saints; ravens of evil spirits; sleep of death, and morning of the resurrection. The vastness of the natural world is a sign pointing to the majesty of God in heaven. Peter Leithart takes a similar approach in Traces of the Trinity, where he explores how the reciprocality and mutual indwelling of seemingly every aspect of human experience—family relationships, language, time, music—point to the nature of the trinity.
Some have suggested that the triune nature of God is reflected in the spirit, soul, and body of man. We can see a parallel to different aspects of God’s nature in Paul’s statement that we are (right now, as believers) seated with God in heaven in Jesus (Eph 2:6), while also walking around, in the flesh, on the earth. The division of soul and body is also seen in the separation of the two at death. As with the contradiction of God’s separation from himself at the cross, there is a sense of something being wrong as long as our souls are separate from the physical realm. Only at the resurrection, when our soul is re-clothed with a glorified body are we made whole (2 Cor 5:1–6; 1 Cor 15:35–44).
The reflection of God’s nature in humanity is clearer still in family relationships: the interconnectedness of mother and child; of husband and wife. The Torah describes the married couple as “one flesh” (Gen 2:24 NIV), and their role in reflecting not only the relationship between Jesus and his people (Eph 5:29–32), but also the internal dynamics of the trinity could help explain the severe view of divorce in the Scriptures (Mal 2:16; Luke 16:18). If the marriage union is a picture of God’s relationship within himself, then divorce bears false witness about God, suggesting that his unity is vulnerable.
The Church, from its early days, was a community in which people with distinct identities and callings came together in “an economy of mutual blessing.” The primary distinction that it overcome was between Jew and Gentile, but as Jewish theologian Michael Wyschogrod observes, it did so not by erasing the distinction between the two, but by embracing and honoring it. This characteristic of the Church was later subverted by centuries of supersessionism and anti-Semitism, but as Soulen writes, “the distinction of Israel and the nations, of Jew and of Gentile, is intrinsic to God’s overarching purpose and work as Consummator of the world.” Paul’s analogies of the Church as the body of Messiah, and of Gentile believers being joined into the commonwealth of Israel describe the same reality (1 Cor 12:12–14; Eph 2:11–22). So Messiah’s Church is composed of distinct parts—the nation of Israel, and every other nation, tribe, and tongue—which nonetheless are one as the bride of Messiah, and the family of God (Eph 5:29–32; 2:19).
The triune nature of God is suggested in passages such as Exodus 19 and Psalm 45. On Sinai, while God Almighty continues to reign in heaven, the cloud of his glory descends, and Adonai comes down to speak with the children of Israel. In the messianic Psalm, God anoints God with “the oil of gladness” (Ps 45:6–7 ESV). In the New Testament the three persons are clear—most famously in Jesus’ baptism, when the Spirit descends like a dove, and the voice from heaven acknowledges Jesus as his son (Matt 3:16–17). Yet there remains a subtlety and an ambiguity to the revelation, so that throughout the New Testament Jesus is frequently called the “Son of God” or “Christ,” but is seldom directly referred to as “God.” When his divinity is plainly seen in the book of Revelation, his distinction from the Father is less clear. The debates of the Church Fathers defining the trinity may have been necessary in their cultural context, but in our postmodern age we may be better served in following the subtlety of the Scriptures. The Bible presents a story of God’s blessing and redemption featuring the character of the God of Israel and the person of the Son of God, the Messiah of Israel, Jesus of Nazareth. I side with Rahner, and with Cyril of Jerusalem, in their related views that God can best be known as he has revealed himself, and that we should be cautious about adding to the Scriptures.
 John Calvin, Institutes of the Christian Religion, trans. Henry Beveridge (Peabody, MA: Hendrickson Publishers, 2008), 1.3.1, 9.
 John E. Smith, Harry S. Stout, and Kenneth P. Minkema, eds., A Jonathan Edwards Reader (New Haven: Yale University Press, 1995), 111.
 Veli-Matti Kärkkäinen, The Doctrine of God: A Global Introduction, 2nd ed. (Grand Rapids: Baker Academic, 2017), 68.
 Alister E. McGrath, Luther’s Theology of the Cross: Martin Luther’s Theological Breakthrough (Grand Rapids: Baker Books, 1990), 148–150.
 Veli-Matti Kärkkäinen, Christology: A Global Introduction, 2nd ed. (Grand Rapids: Baker Academic, 2016), 112.
 Kärkkäinen, Christology, 113. Quoted from Jürgen Moltmann, The Crucified God: The Cross of Christ as the Foundation and Criticism of Christian Theology, trans. Margaret Kohl (Minneapolis: Fortress, 1993), 227.
 Stanley M. Burgess, The Holy Spirit: Ancient Christian Traditions (Peabody, MA: Hendrickson Publishers, 1984), 109. Cited from Cyril of Jerusalem, Catechetical Lectures xvi.24, NPF 2nd series 7:121.
 Kärkkäinen, Doctrine of God, 97–98.
 Richard Bauckham, Jesus and the God of Israel: “God Crucified” and Other Studies on the New Testament’s Christology of Divine Identity (Grand Rapids: William B. Eerdmans Publishing Company, 2008), 8.
 Asher Intrater, Who Ate Lunch with Abraham? A Study of the Appearances of God in the Form of a Man in the Hebrew Scriptures (Peoria, AZ: Intermedia Publishing Group, 2011).
 Michael L. Brown, Answering Jewish Objections to Jesus: Volume Two—Theological Objections (Grand Rapids: Baker Books, 2000), 54.
 Brown, Answering Jewish Objections to Jesus: Volume Two (Grand Rapids: Baker Books, 2000), 13.
 Smith, Stout, and Minkema, A Jonathan Edwards Reader (New Haven: Yale University Press, 1995), 16–21.
 Peter J. Leithart, Traces of the Trinity: Signs of God in Creation and Human Experience (Grand Rapids: Brazos Press, 2015).
 R. Kendall Soulen, The God of Israel and Christian Theology (Minneapolis: Fortress Press, 1996), 111.
 Soulen, The God of Israel and Christian Theology, 11. Wyschogrod’s views are cited from Michael Wyschogrod and David Berger, Jews and Jewish Christianity (New York: KTAV, 1978), 64f.
 Soulen, The God of Israel and Christian Theology, 117.
 Michael L. Brown, Answering Jewish Objections to Jesus: Volume Three—Messianic Prophecy Objections (Grand Rapids: Baker Books, 2003), 131.