Robert Letham’s Union with Christ is a good overview of a subject that is vital for understanding how we receive all the benefits Christ procured through earthly life and death. One of the things I appreciate about his approach is the way he defines “union in Christ” in covenantal categories. Even if appeals to the classical “covenant of grace” / “covenant of works” approach to the biblical covenants, his approach rightly assigns “union in Christ” to a covenantal concept.
Of late, I have heard some people speak about “union in Christ” and Christ’s mediation (a la 1 Timothy 2:5) without paying attention to the biblical idea of the covenants. Letham corrects this sort of approach. He shows how “union in Christ” cannot be explained our understood apart from understanding Christ as a “covenant head” and someone who is united to us in a “covenantal” relationship. Here is how he summarizes his understanding of Union in Christ:
In The Holy Trinity, Robert Letham quotes Gregory Nazianzen’s cogent statement on the Trinity’s progressive revelation within the history of the Bible:
The Old Testament proclaimed the Father openly, and the Son more obscurely. The New manifested the Son, and suggested the deity of the Spirit. Now the Spirit himself dwells among us, and supplies us with a clearer demonstration of himself. For it was not safe, when the Godhead of the Father was not yet acknowledged, plainly to proclaim the Son; nor when that of the Son was not yet received to burden us further…with the Holy Spirit…[I]t was necessary that, increasing little by little, and as David says, by ascensions from glory to glory, the full splendor of the Trinity should gradually shine (Robert Letham, The Holy Trinity, 33).
Gregory’s insights draw attention to the the wisdom of Christianity’s Triune God as he has gradually revealed himself as he really is and always (read: eternally) has been–God the Father, God the Son, and God the Holy Spirit. While all three existed in eternity together, only in the fullness of time is Triune Godhead seen in his manifold perfections. For those who read and teach the Bible, it must be kept in mind that God’s revelation is accomplished over time, and that the unchanging deity of the Bible is more clearly disclosed at the end of the story than at the beginning. While Gen. 1:1, 2, 3 arguably contain allusions to all three members of the Trinity, their disclosure is opaque, at best. This does not make Scripture contradictory or confused; it must be read in time (diachronically).
The progressive act of Trinitarian revelation shows God’s wisdom in teaching us, finite creations, who he is through escalating stages of revelation (cf. Heb. 1:1-3). Until we see how redemptive-history develops the Trinity over time, we will not be able to fully appreciate the oneness and the threeness of God–one Trinitarian being, three consubstantional persons; co-eternal in nature, fully revealed in their inter-penetrating distinctives in time.
There is so much here to fathom. May we continue to marvel at the uniqueness, the mystery, and the revelation of our living and true God.
Sola Deo Gloria, dss
In The Holy Trinity, Robert Letham refers to T.F. Torrance’s assertion that John Calvin’s Trinitarian theology was developed, in part, by the Trinitarian formulations of Gregory Nazianzen. That is a mouthful, and an amazing pedigree–Gregory Naz, John Calvin, T.F. Torrance, Robert Letham (p. 267). Though Torrance’s connection between Gregory and Calvin has been debated by some (cf. Tony Lane), Calvin was at least familiar with Greg Naz, as is shown in the following quotation in Calvin’s writings.
I encourage you to meditate on Gregory’s unity and diversity held together in this Trinitarian reflection. Speaking of God the Father, God the Son, and God the Holy Spirit, the Cappadocian father writes:
No sooner do I conceive of the one than I am illumined by the splendour of the three; no sooner do I distinguish them than I am carried back to the one. When I think of any one of the three I think of him as the whole, and my eyes are filled, and the greater part of what I am thinking escapes me. I cannot grasp the greatness of that one so as to attribute a greater greatness to the rest. When I contemplate the three together, I see but one torch, and cannot divide or measure out the undivided light.
May we continue to delight in the immeasurable perfections of our Triune God.
Sola Deo Gloria, dss