Should Christians in their life together as an ecclesiastical community reflect the trinitarian communion which is constitutive of the very being and life of God? In other words, does the Bible make the life of God as Father, Son, and Holy Spirit a model or archetype of redeemed humanity’s communal relations? I believe so. The personal relations between and the fellowship of Father, Son, and Holy Spirit are paradigmatic for ecclesial life and fellowship. How Christians relate one to another should mirror the loving relations within the Godhead. Moreover, beyond our love for one another, the church images the Trinity when she extends that love to those outside of her fellowship and seeks to draw outsiders into the fullness of life she enjoys in union with the Triune God.
Many in the Reformed community, however, remain at best suspicious of theologizing about the church in the light of the Trinity. Even though a great deal of theological work has already been done in modern times on the social nature of God’s eternal trinitarian life and being, most of that work has been done outside of traditional Reformed theological circles in the later half of the twentieth century. Traditional Reformed theologians and pastors have not been on the cutting edge of modern trinitarian theology, and therefore have not often been comfortable with using the results of socially construed theologies of the Trinity to think about the life of the church. A quick, informal search of theological journals published by institutions associated with orthodox confessional Protestantism uncovers little or no interest in the connection between the Trinity and the Church.
Note: There are a few exceptions. One of the few Reformed theologians that has written at length on this topic is Cornelius Plantinga, Jr., “The Hodgson-Welch Debate and the Social Analogy of the Trinity” (Ph.D. diss., Princeton Theological Seminary, 1982); “Gregory of Nyssa and the Social Analogy of the Trinity,” The Thomist 50 (1986): 325-352; “Social Trinity and Tritheism,” in Trinity, Incarnation, and Atonement; “The Threeness/Oneness Problem of the Trinity,” Calvin Theological Journal 23 (1988): 37-53; “The Perfect Family: Our Model of Life Together is Found in the Father, Son, and Holy Spirit,” Christianity Today 32 (Nov. 4, 1988): 24-27; and “Images of God,” in Christian Faith and Practice in the Modern World: Theology from an Evangelical Point of View, edited by M. A. Noll and D. F. Wells (Grand Rapids, MI: Eerdmans, 1988), pp. 51-67. There is also Donald Maccleod's slim, but useful book Shared Life: The Trinity and the Fellowship of God's People (Greenville, SC: RAP, 1987).
Perhaps what is not explicitly dealt with in our own confessional books will always be viewed with suspicion. As far as I can tell, neither the confessions nor the catechisms of the Reformation and Protestant Scholasticism explicitly connect the Church’s common life together with God’s communal life as Father, Son, and Holy Spirit. No doubt, this lacuna within the symbolic books of the Reformation reflects the fact that the Reformers themselves, while affirming and defending the Trinity, and clarifying its defining significance for the divine-human relationship, nevertheless, did not attempt to develop a trinitarian theology of human-human relationships within the church. This second theological move, although hinted at by earlier, pre-Reformation trinitarian theologians, has only begun to be explored by modern theologians in tandem with the blossoming of interest in what has been called “social trinitarianism” in the 20th century.
Note: Only here and there do we find hints of the possibility of a trinitarian ecclesiology in patristic and medieval theology (Tertullian, Ad Praxeas, chpts. 20-25; Cyprian, Ep. 74 [ANF, p. 390-1]; Augustine, de Trin. 4.12; 6.4; Richard of St. Victor, de Trin. 3.9). John Thompson notes that “in the patristic era there were clear signs showing an awareness of the church as a trinitarian reality emphasizing the mystery of God’s being and action, creating the unity and fellowship of the church reflecting his own divine life” (Modern Trinitarian Perspectives [New York: Oxford, 1994], p. 80). Nevertheless, Thompson’s own analysis relies on the work of Heinz Schutte, who argues in his Im Gespräch mit dem Dreieinen Gott (Düsseldorf: Patmos Verlag, 1985) that the trinitarian dimension of ecclesiology remained largely implicit in patristic and medieval theologians (pp. 361-375). What lay dormant in these early trinitarian theologies has been made a theological research program in the 20th and 21st century.