Francis Turretin,
Institutes of Elenctic Theology
III.xxvi, vol. 1, pp. 272-277.

Can the mystery of the Trinity be proved from the Old Testament, and was it known under it? We affirm against the Socinians.

I. From the arguments adduced by us before to prove the necessity of this doctrine as a fundamental article, it might be satisfactorily inferred that it was revealed and known under the Old Testament (since fundamentals are the same among all believers admitting neither of increase nor of diminution). Yet the Socinians (in order by any means to destroy the belief of this mystery) are wont to urge peculiarly that it is a new doctrine invented after the time of Christ and his apostles (whom the Arminians also carry on their shoulders here). It therefore becomes necessary to establish against both the truth of this mystery not only from the New, but also from the Old Testament.

The Trinity was not unknown under the Old Testament.

II. Indeed, we confess that it was not revealed under the Old Testament with the same clearness as it is now taught in the New. It was delivered far more obscurely because the reason of that economy and the (as yet) infantile condition of the ancient church required it. Yet this is no objection to its having been made known even to the patriarchs sufficiently for salvation. The orthodox thus far have constantly asserted this against the Socinians, and it can be proved by various arguments.

III. For the proof we must make a choice of the passages of Scripture that we may contend not so much by number as by weight. For it is not becoming in us to be so anxious about the number as about the solidity, lest the Christian religion be exposed to derision and an opportunity of cavilling be afforded to the adversaries. When our Calvin labored to do this, he was undeservedly and most unjustly traduced by them as a Judaizer or an Arianizer. On the contrary, scarcely has anyone more strongly and triumphantly confirmed the Christian faith against the impiety of the Arians and the Jews.

A Plurality of persons is proved from Gen. 1:26, etc.

IV. But as God has condescended to reveal himself here “at sundry times and in diverse manners” (polymerōs kai polytropōs), there is a double kind of proof. First, we may adduce those passages from which a plurality of persons may be gathered; second, those in which the Trinity is expressly mentioned. Among the former are a large number which introduce God speaking of himself in the plural number. The principle ones are these three: at the creation of man, “Let us make man in our image” (Gen. 1:26); at the transgression of Adam, “Behold, the man is become as one of us” (Gen 3:22); and at the confusion of tongues, “Let us go down and there confound their language” (Gen 11:7). No reason can be assigned why God (who elsewhere so frequently speaks of himself in the singular) should use the plural verb, unless to intimate a certain (at least) plurality of persons in the unity of essence. Hence he does not say “let me make,” but “let us make,” so that more than one is intimated. As in creating, there is a common operation to them, so there ought to be a common nature. He does not say in “images,” but in “our image,” so that the identity of image designates the identity of essence common to these more than one. Nor ought it to be objected here: (1) that God for the sake of honor speaks of himself in the plural by enallage (like kings and princes) because the idiom of the language forbids it. For although the second or third person can be so addressed for the sake of honor, yet it is altogether unusual for the first person to speak thus of himself (as Aben Ezra himself on Genesis 29:27 remarks). Nor can any example to the contrary be adduced. Those which are sought from various passages of Scripture are synecdochical, where one speaks in the name of more: Laban of himself and friends who were present (Gen. 29:27); Bildad of himself and companions (Job 18:2, 3); Daniel of himself and companions (Dan. 2:36); Christ of himself, John the Baptist and his disciples (John 3:11); the church of herself and daughters (i.e., believers, Cant. 1:4). The present custom of kings does not imply that this practice existed among the Hebrews, since Pharoah, Nebuchadnezzar, Belshazzar and the most ambitious kings are introduced speaking of themselves in the singular. When kings do thus speak, it is done not so much for the purpose of exalting as of depressing themselves, that they may seem to speak not only of themselves, but also the opinion of the nobles. (2) If God spoke thus of himself for the sake of honor, he ought always to have spoken so (which he certainly did not do). Third, this enallage would be not only useless but also dangerous because the believer would thus be easily induced to believe a plurality of persons (which however would be false on that hypothesis).

V. Of no force either is the objection that angels are here addressed because in none of the three passages can they be understood. Not in the first (Gen. 1:26), because the angels neither assisted in the least in the creation of man nor is he anywhere said to have been formed in their image. Although men are in various respects similar to the angels, yet they cannot be said to have been made in their image because for this would be required no kind of similitude, but also a dependence of the type upon the prototype and exemplar (which does not occur here). Not in the second (Gen. 3:22), because those whom God addresses are equal to him and their likeness (man) aimed at according to the promise of the serpent (which cannot be said of the angels). Not in the third (Gen. 11:7), because they are addressed whose work is the confusion of tongues (which does not pertain to the angels, but to God alone). Besides the deep silence here concerning the angels, Jehovah alone is said to descend, to see, to confound (which ought not to have been said if he had employed angels as his ministers in this work).

2. From Gen. 1:2.

VI. Second, a plurality may be proved from those passages where the discourse concerns God as about different persons. “The Spirit of God” (Gen. 1:2) is said to move upon the face of the waters. By the Spirit cannot be understood the “air” or “wind” because neither had as yet been created. And no distinction of things had been made, nor any angel because it is not known whether angels had as yet been created (nor is God said to have used their help in creation). Nor can it be understood of any virtue and efficacy of God as the cause of the fecundity of things because that is described by incubation and is distinguished from the Spirit (as the effect from the cause and actions belong to self-existent things [sup-positorum]). Therefore by the Spirit must necessarily be meant some suppositum or person concurring to this work; to wit, the same Spirit who is elsewhere termed the author of creation (Ps. 33:6; 104:30; Is. 40:13, 14, expressions applying to no created thing). Nor is it an objection that he is called the Spirit of God for he is so the Spirit of God considered hypostatically as to be also God the Spirit essentially (ousidōdōs) as the Son of Man is also man. Nor if that incubation (as an external work) is common to the whole Trinity originally does it follow that it cannot belong appropriatively to the Holy Spirit because he performs it immediately and by himself (although from the Father and the Son); just as redemption (which is ascribed to the whole Trinity) yet singularly and terminatively is attributed to the Son.

From Hos. 1:7. 

VIl. The same thing may be proved from those passages in which God is distinguished from himself, not essentially but personally. Jehovah says, “I will save them by Jehovah their God” (Hose 1:7). Where two are spoken of—one who saves, another by whom he saves (viz., the Messiah)—and both Jehovah. “Jehovah rained fire and brimstone from Jehovah” (Gen. 19:24), i.e., the Son from the Father For if he had wished only to denote that this had been done immediately by God, it would have sufficed to say Jehovah rained without adding “from Jehovah.” Therefore undoubtedly a mystery lies concealed in this locution, although an apodictical argument cannot be drawn from this passage taken by itself, So “Jehovah said to my Lord” (Ps. 110:1) and “God, thy God, hath anointed thee with the oil of gladness” (Ps. 45:7), where mention is made of God anointing and anointed (viz., hypostatically not essentially). Here belong the passages in which divine names and attributes are ascribed to the Messiah: when he is called “Jehovah our righteousness,” “the mighty God,” “the angel of his presence.” These manifestly prove a divine person distinct from God the Father. Nor can the heretics bring forward anything here to weaken the force of this argument, as will be shown in the proper place when we come to treat of the deity of the Son.

The Trinity may be proved from Gen. 1.

VIII. As the passages which connote a plurality of persons are various, so those in which that plurality is restricted to a Trinity are not few. First, it is collected with some clearness from the history of the creation the where Moses distinctly mentions Elohim creating, Spirit of God moving upon the waters, and the Word producing all things. That Elohim is God, the adversaries do not deny; that the Spirit of God is a person distinct from him has been already proved; and that the Word is not a simple command and mandate of God, but a personal Word is evinced by a comparison Moses with John who, alluding to Moses, describes the Word spoken of by Moses as a person subsisting with God the Father, by whom all things were created (John 1:1-3). Nor can it be understood either of “an external word” by which God commanded the angels as his ministers because they were not yet created—they themselves ought to be produced by that Word who made all things without exception; or of an internal word by which he enjoined this upon himself—because God is introduced speaking in the third person, as if commanding another person not himself (and that too repeatedly). This cannot be explained as being done either undesignedly or in accommodation to an internal word. It remains therefore that we must understand a “personal Word” (i.e., the Son of God, who is often set forth in the Chaldee paraphrase by mymr or “the Word“). Nor is it an objection that the verb “said” connotes an efficacious command of God. For although objectively and terminated on the creatures about to be produced, it implies the efficacious command of God (to whom they would owe their origin), yet it supposes within and originally the personal Word of God as the principle which that mandate ought to obey (as by him he works all things and made the worlds, Heb. 1:2): In reference to this David says, “By the word of the Lord were the heavens made; and all the host of them by the breath of his mouth” (Ps. 33:6). Here distinct mention is made of three concurring in creation: “Jehovah,” “the Word” and “the Spirit.” For the Word can be no other than that by whom John says all things were made (John 1:3). Nor can any other Spirit be meant than him who moved upon the waters in the first creation (Gen. 1:2). And if the Spirit of the mouth of God is elsewhere usually applied to his efficacious word (cf. 2 Thess. 2:8), it ought here also to be taken in the same sense; since such express mention had been made of him in the first part of the verse.

2. From the liberation of the people from Egyptian bondage. 

IX. Second, the same may be proved from the deliverance of the people out of Egyptian bondage, the guidance of them through the wilderness, and introduction into Canaan. He is that true God whom the Israelites acknowledged and worshipped, who brought them out of Egypt, lead them through the wilderness and introduced them into the land of promise. For no other besides God could have performed so great a work, as he himself testifies in the preface to the law: “I am the Lord thy God who brought thee out of the land of Egypt.” Also he often claims this as his prerogative (Ex. 3:8; Dt. 33:29). Now this work is ascribed to the three persons of the Trinity—the Father, the Son and the Holy Spirit. Concerning the Father, the adversaries do not doubt; concerning the Son, the following passages prove (Ex. 3:2; 23:20; 32:34), in which this work is ascribed to the “angel of Jehovah.” That this angel is not a created angel, but the uncreated Son of God himself, sent by God for this work and often manifesting himself under this form to the patriarchs, is evident from the description of him and the various attributes given to him (which are such as cannot apply to a creature, but belong to God alone). (l) He says he is the God of Abraham, of Isaac and of Jacob (Ex. 3:6); calls the Israelites his people (Ex. 3:7); sends Moses to Pharaoh (Ex. 3:10); promises himself divine worship after their deliverance from Egypt (Ex. 3:12). (2) He is said to have gone before the Israelites in a pillar of cloud and fire (Ex. 14:19), which is expressly attributed to Jehovah (Ex. 13:21; Num. 11:25; 14:14). (3) It is said that “the name of God” will be in him so that they will not escape unpunished who rebel against him (Ex. 23:20, 21*). (4) He is called “the very presence of God” (“My presence shall go with thee,” Ex. 33:14) because he is the image of the invisible God, the express image of the person of the Father. That the Holy Spirit also here concurred as a person with the others is evident from the noted passage: “I will mention the lovingkindnesses of the Lord” (Is. 63:7e14). He said “surely they are my people, so he was their Savior’ “The angel of his presence saved them in his love, but they rebelled and vexed his Holy Spirit.” Here three distinct persons are enumerated: “Jehovah,” “the angel of his presence,” and “the Holy Spirit.” Distinct operations are ascribed to each: to Jehovah, lovingkindness towards the people; to the angel of his presence, redemption; and to the Holy Spirit, vexation and contention with the people, while he was turned to be their enemy. Since, then, a truly divine work is ascribed to these three, it is necessary that they should be the one true God essentially (although mutually distinguished in mode of subsisting and personally).

3. From the descriptions of the Messiah. 

X. Third, the same thing is evidenced by the descriptions of the Messiah. Since he is everywhere proposed not only as the seed of the woman and the fruit of the womb (i.e., a true man), but also as the true and eternal God, to whom divine names and attributes and works are ascribed (as will be demonstrated hereafter), who was to be sent from the Father and the Holy Spirit, it is evident that the mystery of the Trinity was thus revealed with sufficient clearness. Here belongs the passage, “The Spirit of the Lord God is upon me; because the Lord hath anointed me to preach good tidings unto the meek” (Is. 61:1, 2). Christ himself authorizes us to refer these words to the Messiah (Lk. 4:21); nor can the Jews, although obstinate, deny it. Such things are predicated of him as can apply neither to Isaiah nor to any other mortal. As therefore the work ascribed to the Messiah proves him to be God, so when mention is made of Jehovah and his Spirit sending and anointing him, two persons distinct from him are connoted. The passage in Haggai 2:4, 5* is pertinent here, which mentions these three: “I am with you, saith the Lord of hosts: according to the word that I covenanted with you, so my spirit remaineth among you.”

4. From the threefold repetition of the name Jehovah, Num. 6:24-26.

XI. Fourth, from the threefold repetition of the name Jehovah, as in the blessing of the priest: “The Lord bless thee, and keep thee: the Lord make his face shine upon thee, and be gracious unto thee: the Lord lift up his countenance upon thee, and give thee peace” (Num. 6:24-26). For this threefold repetition can be employed for no other purpose than to designate those three persons from whom, as from one true Jehovah, that blessing is sought. Thus Jacob mentions three times the God from whom he seeks a blessing for his sons: “God, before whom my fathers did walk; the God which fed me all my life long unto this day’ the Angel which redeemed me from all evil, bless the lads” (Gen. 48:15, 16). Now the angel who redeemed him from all evil and from whom he sought the blessing could not be a creature. Here also must be referred the seraphic trisagion: “Holy, holy, holy is Jehovah God of Hosts” (Is. 6:3). For although this threefold repetition can denote the unwearied assiduity Of the heavenly inhabitants in praising God and the excellency of the divine holiness, still this does not hinder it from being considered as also designating a sacred Triad. The latter may be gathered from this—that these are ascriptions to Jehovah, the plurality of whose persons is implied even from this—not only that he says, “Who will go for us” (Is. 6:8), but also that the mandate issued there is to be attributed not only to the Father, but also to the Son and Holy Spirit (from a comparison of Jn. 12:41 and Acts 28:25, where the things spoken here of Jehovah are attributed to the Son and the Holy Spirit, who consequently are understood to be designated in this trisagion). To no purpose does Volkelius endeavor to destroy the argument from those passages where a threefold repetition is found (as Jer. 27:4, 22:9; Ezk. 21:32) because it is not founded simply upon the repetition, but upon that in connection with other circumstances of the text.

XII. Fifth, to these must be added those passages from which the divinity of the Son and of the Holy Spirit is proved (of which we will treat hereafter when we take up their divinity). These would have no force, unless a Trinity of persons in unity of essence had been connotated.

XIII. Sixth, there is not one Old Testament and another New Testament God (as the Marcionites and Manicheans formerly pretended), but one and the same revealed in both as the sole object of faith and worship. Under the New Testament, he has revealed himself as one in essence and three in persons. Therefore he must necessarily have been revealed to the Jews as such and known and worshipped by them. Otherwise they would not have worshipped the true God who is no other than the Father, the Son and the Holy Spirit (because he who has not the Son has not the Father either, 1 Jn. 2:23).

XIV. Finally, if the Trinity was not revealed in the Old Testament, the orthodox thus far (the ancient as well as the more modem) have labored falsely to prove it from the Old Testament (which cannot without grievous injustice be charged upon so many great men and faithful servants of God). Nor ought it to be said that we can now indeed gather this from the Old Testament assisted by the light of the gospel; but that it could not be done equally by the fathers. For although we confess that the light of the New Testament serves in a great measure to illuminate for us the obscurity of the ancient oracles, yet it cannot be denied that God, who condescended to reveal them to the fathers for their instruction and consolation, adapted them to their comprehension so that they might from them be instructed in this mystery (as far as was necessary for their salvation). Otherwise to no purpose were these things revealed to them.

XV. Although the Jews of our day refuse to acknowledge this mystery, it does not follow that it was unknown under the Old Testament (no more than the various Other mysteries which are denied by them now, although it is certain that they were formerly revealed). For the knowledge of a thing ought not to be measured by the ignorance of this or that subject, but by the revelation made in the word. In addition, the modern Jews, bearing a veil of unbelief over their hearts and bewitched by the nefarious hatred with which they persecute our Messiah, voluntarily shut their eyes to that light which the ancient believers, not blinded by prejudice, contemplated with great consolation, assisted by the Holy Spirit. red from this persons is implied in unity of essence had been con notated to prove it from the old testament ( which cannot without grievous injustice otherwise to no purpose were these things revealed

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Francis Turretin, Institutes of Elenctic Theology, trans. George Musgrave Giger, ed. James T. Dennison, Vol. 1, Phillipsburg, New Jersey: Presbyterian and Reformed Publishing, 1992, pp. 272-7.

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