What does it mean to say that the doctrine of the Trinity is a biblical doctrine? Benjamin Breckinridge Warfield’s “Trinity” entry in The International Standard Bible Encyclopaedia provides an instructive response to this question. Originally published in 1915, within a largely Ritschlian context that regarded doctrines like the Trinity as later corruptions of an originally undogmatic Christian religion, Warfield’s article presents his mature account of the biblical bases of the church’s Trinitarian confession. Warfield examines the major biblical texts from which the doctrine of the Trinity is drawn. He surveys Old Testament passages commonly adduced by the “older writers” (e.g., Gen. 1:26; Num. 6:24, 26; Ps. 110:1; Prov. 8), as well as those adduced by “more recent authors,” including texts which portray the operation of a threefold divine cause in “the first . . . and the second creation” (e.g., Ps. 33:6; Isa. 61:1; 63:9–12; Hag. 2:5–6).
Warfield also surveys various New Testament passages, considering the contributions of the Synoptic Gospels, the Johannine and Pauline writings, and the Catholic Epistles to Trinitarian doctrine. In each instance, he is careful to acknowledge the distinctive idiom of each New Testament author and to defend the authenticity of key Trinitarian proof-texts (e.g., the Trinitarian baptismal formula of Matt 28:19).
Warfield’s ISBE entry on the Trinity is not merely an examination of Trinitarian proof-texts. Over the course of the article, the Princeton theologian offers a series of sophisticated judgments regarding the underlying hermeneutical logic that informs, and is informed by, exegesis of those texts. He discusses the legitimacy of using extra-biblical terminology to convey biblical teaching, the role of reason in Trinitarian doctrine, the relationship between the Old and New Testaments within the Trinitarian economy of revelation, and the variety and significance of biblical terminology in relation to its triune referent. Ultimately, according to Warfield, the doctrine of the triune God follows from the revelation of the triune God in the redemptive work of the triune God. In other words, the doctrine of the Trinity is revealed to us “in the incarnation of God the Son and the outpouring of God the Holy Spirit.” The New Testament is the literary sign that the early church embraced this revelation of the triune redeemer and the literary expression of its universal Trinitarian consciousness.
Warfield summarizes the main lines of biblical teaching on the Trinity in three points: (1) “there is but one God,” (2) “the Father and the Son and the Spirit is each God,” and (3) “the Father and the Son and the Spirit is each a distinct person.” “When we have said these three things,” he insists, “we have enunciated the doctrine of the Trinity in its completeness.” Warfield’s summary is unremarkable when placed alongside later Reformed and evangelical syntheses of the doctrine. Wayne Grudem, for example, basically repeats Warfield’s three-point summary in his Systematic Theology, as does Robert Reymond. However, viewed in relation to earlier statements of the doctrine, including those of Warfield’s Presbyterian Church (WCF 2.3), his summary lacks the “completeness” he claims for it. Specifically, Warfield omits any mention of the so-called “personal properties” which distinguish the divine persons from one another, namely, the Father’s eternal begetting of the Son (“paternity”), the Son’s eternal generation from the Father (“filiation”), and the Spirit’s eternal procession from the Father and the Son (“spiration”).