The Trinity

The self-revelation of God in Scripture that His indivisible, personal essence exists eternally and necessarily as Father, Son, and Holy Spirit, and that these three are not merely nominal distinctions but personal subsistences in the divine essence.

Dr. South said that if you try to comprehend the doctrine of the Trinity, you may lose your mind, and if you deny it you will lose your soul. The finite mind of man cannot possibly comprehend the infinite God. So a complete understanding of the doctrine of the Trinity is not attainable by us. However, we may obtain a knowledge of the Trinity from God’s revelation of Himself in His word, and although the knowledge so gained by our finite minds is incomplete, it is nonetheless true knowledge.

God’s revelation of Himself lies at the heart of all He has revealed in His word. In a very real sense, our understanding of any part of the Scripture revelation is dependent upon our acceptance of God’s revelation of Himself, a revelation which is denoted by the term Trinity. It has been aptly said, “The Trinity is the point in which all Christian ideas and interests unite; at once the beginning and the end of all insight into Christianity.”

Defining Our Terms

Trinity. “The word trinity is derived from Latin and Greek terms meaning three in one, or the one which is three, and the three which are one.… The word is not found in the Scriptures. Technical terms are, however, absolutely necessary in all sciences. In this case they have been made particularly essential because of the subtle perversions of the simple, untechnical Biblical statements by infidels and heretics. The term, as above defined, admirably expresses the central fact of the great doctrine of the one essence eternally subsisting as three Persons, all the elements of which are explicitly taught in the Scriptures” (A. A. Hodge, Outlines of Theology).

Person. The original meaning of the Latin word persona is far removed from its present sense and it is an even larger step from the present sense of the word to the scriptural and theological meaning when applied to the Godhead. But despite its imperfection as a term, there is none better in man’s vocabulary. In everyday usage, the term person denotes an entirely separate and distinct rational individual. It does not have this meaning when referred to the persons in the Trinity. A divine person, to use John Calvin’s words, is “a subsistence in the divine essence—a subsistence which, while related to the other two, is distinguished from them by incommunicable properties.”

Deniers of the Trinity

These fall into two main classes:

1. Arians and Socinians, who deny the deity of Christ and of the Holy Spirit.

2. Sabellians who hold that the Biblical Trinity is an economical one, not an essential one. That is, the names Father, Son, and Holy Spirit are different names for the one divine person under different relations or fulfilling different offices.

It is commonly, and mostly frivolously, objected that the doctrine of the Trinity makes three Gods, while the Scripture teaches “there is one God.” Another objection is that God cannot be both one and three. Such objections either miss the point or set out to misrepresent the orthodox position.

The doctrine of the Trinity emphasizes the unity of the divine essence. What theologians call His “numerical essence” is one and indivisible. Each trinitarian person possesses the undivided essence, not a fragment of it. To imagine the three persons of the Godhead each having a third of the divine essence is an absurdity, for infinity cannot be fragmented or fractionalized. As the Shorter Catechism put it, “There are three Persons in the Godhead, the Father, the Son, and the Holy Ghost: these three are one God, the same in substance, equal in power and glory” (Q. 6).

Again, the doctrine of the Trinity does not teach that God is one and three in the same sense. Obviously that would be absurd. However, there is no contradiction in saying that God is one as to His eternal spiritual essence and that that divine essence exists necessarily in three modes, each of which is spoken of in Scripture in personal terms.

Furthermore, we do not hold that God is three and one, but that He is three in one, and one in three. We state the doctrine this way, not because we can understand it (if any mind could understand the infinite God, that mind itself would be infinite), but because the word of God warrants such statements. Indeed, the teaching of the Scriptures concerning God cannot be fully and faithfully interpreted apart from such trinitarian statements.

Scripture Proof of the Doctrine of the Trinity

To prove the Trinity we need prove only the following propositions from Scripture:

1. That God is one. Deuteronomy 6:4 establishes that beyond all doubt: “The Lord our God is one Lord.”

2. That the Father is truly God, that the Son is truly God, and that the Holy Spirit is truly God. 1 Corinthians 8:6 teaches “there is one God the Father”; John 1:1–3 clearly established the proper deity of the Son; while Acts 5:3–5 does the same concerning the Holy Spirit.

3. That yet the Father is not the Son; the Son is not the Father; and neither of them is the Holy Spirit.

This can be clearly seen from the plain statements of Scripture. Consider the following evidence:

Genesis 1:26: “And God said, Let us make man in our image, after our likeness.” Up to this point in the creation story, God has used the language of command, but now He uses the language of consultation. With whom is He taking counsel? We answer, with Himself in the persons of the blessed Trinity.

To avoid this evidence of eternal personal distinctions in the Godhead, some hold that here God consults with angels. Absurd! Where does the Scripture ever teach that angels had a part in the creation of man? The Scriptures do teach, however, that the divine persons in the Godhead were active in creation (Gen. 1:2, referring to the Holy Spirit, and John 1:1–3, referring to the Son). What proves that God consulted with Himself and not with angels, is the statement of Gen. 1:27, “So God created man in his own image,” with no mention of angels at all.

If God consulted with Himself, what can the significance of the us be, except to emphasize a real plurality of persons in the Godhead?

Isaiah 48:16: “The Lord God, and his Spirit, hath sent me.” The context after v. 12 shows that the speaker is Messiah. He is clearly a divine person because in v. 12 He says, “I am he; I am the first, I also am the last” (compare Rev. 1:8, 11–13). In v. 16 He says, “From the time it was, there am I and now the Lord God, and His Spirit, hath sent me.” What stronger evidence could be given of three divine persons, distinct one from another as to their personal properties, in the unity of the divine essence?

Many other Scriptures may be cited showing the Father speaking to the Son and vice versa, and all these would be added proof that the Father and the Son are so far distinguished as to be able to hold conversation one with another.


Since there is one God, and since the Father is God, the Son is God, and the Holy Spirit is God, and since these three are clearly distinguished in Scripture, we are left with the glorious truth of the Trinity—one God eternally existing as Father, Son, and Holy Ghost, each indwelling the other and each possessing, not in part, but entirely, the infinite essence of the one divine Being. Contemplating such a majestic mystery of revealed truth, we are constrained to cry out with heaven’s seraphim, “Holy, holy, holy, is the Lord of Hosts” (Isa. 6:3).

Note: Check back for more information on this holy subject.

Cairns, A. (2002). In Dictionary of Theological Terms. Belfast; Greenville, SC: Ambassador Emerald International.
Exported from Logos Bible Software, 4:17 PM February 8, 2016

Return to Index of Concepts and Definitions

Return to CRTA