The Trinity: An Overview, Revealed by the Son

Why don’t we immediately see God the Holy Trinity jumping from the pages of Old Testament scripture?

It is a sincere question a Muslim, a Jew and even a newer Christian all may ask.

Reading the Old Testament by its own light, not by the light of the New, may push us to regard God as an undifferentiated divine being instead of the Father, the Son, and the Holy Spirit.

The reason we do not immediately see the Trinity in the Old Testament is because the revelation of the Trinity is mediated through Jesus Christ. The Father was pleased to honor the Son by saving the privilege of revealing God’s inner life until the fullness of time had come and the Son appeared.

In a beautifully succinct Trinitarian statement the apostle Paul tells believing Jews and Gentiles in the church at Ephesus: “For through him [Jesus] we both have access in one Spirit to the Father” (Ephesians 2:18).

The access Christ has obtained for us and given to us is both access to a fuller knowledge of God and to the redemptive benefits of God – God the Holy Trinity. One can only come to know God as he is by coming to know Jesus Christ who graciously makes himself known to ignorant sinners.

In an exquisitely argued essay found in the book, God the Holy Trinity: Reflections on Christian Practice and Faith (Baker Academic, 2006) theologian Gerald Bray advances a helpful metaphor to explain the progress of biblical revelation concerning God. [Please note: progress in biblical revelation should never be mistaken for the same as progress in God. The infinite, eternal and unchangeable God does not develop, however, his revelation of himself does.]

Bray’s metaphor is that of a husk and a kernel.

“[The apostle Paul] regarded the Mosaic law as a kind of covering, which God introduced in order to keep the wayward Israelites on the straight and narrow way. Unfortunately, later generations had come to mistake the husk for the kernel and so they had fundamentally misinterpreted the true meaning of the Scripture. The coming of Christ did away with the husk, opening up the kernel to give us direct access to God” (p. 45).

Having accomplished the long-promised redemption of God’s covenant people, Christ now takes us behind the veil where we now know God to be “a Trinity of mutually related persons, and a unity of equal essence” (Augustine, On the Trinity). This is the kernel, the fruit, the life. There is no kernel behind this kernel. The revelation of God culminates in the Son (Heb. 1:2).

Now we should be clear: God did not become the Trinity through Christ’s mediation. The triune God is eternally triune. Yet it was only through Christ’s mediation that what has always been true of God and known to God alone has become known to us. 

Through Jesus Christ, justified sinners are brought further into the life of God than ever before. This is not just illustrated but demonstrated by the veil of the Jerusalem temple being torn the moment Jesus breathed his last breath. The event is reported by Matthew, Mark and Luke.

The veil blocked the way into the earthly holy of holies, separating sinful men from access to God except by a mediator, the appointed priest. Now - through his death, resurrection and ascension – Jesus Christ, high priest forever, has entered the holy place not made with hands (Heb. 9:24). All who are in Christ by faith go with him and so come to meet, know, worship and adore the Triune God.

Here is Bray one more time:

“To put it another way, whereas ordinary Jews were kept out of the holiest place in the temple, Christians have been admitted into the inner life of God. Only in that context, and based on that understanding, can we reconcile Christian theology with the Old Testament revelation. The God who appears as One to those who view him on the outside, reveals himself as a Trinity of persons, once his inner life is opened to our experience.”

To put it even another way, the revelation of God as Trinity is a profoundly intimate Word from God – the giving of God himself (John 1:1; Hebrews 1:2).

What is the best way then to describe the experience of an ordinary man who has been brought, through the living Word, Jesus Christ, into the inner life of God? The apostle hits that note pitch perfect: “And because you are sons, God has sent the Spirit of his Son into our hearts, crying, ‘Abba! Father!’” (Gal. 4:6).

John Hartley has been pastor of Apple Valley Presbyterian Church since 2010, having previously been a pastor for 10 years in Vermont. He is a Wisconsin native and a graduate of University of Wisconsin-Milwaukee as well as Dallas Theological Seminary. John lives with his wife Jen and their five children.