What is the origin of the doctrine of the Trinity?

It is quite true that this could not be comprehended at the time. It was not indeed until the baptism of our blessed Lord that the whole truth of the Trinity came out. Then God spake from heaven; His beloved Son was on the earth; and the Holy Ghost descended and abode upon the Son. But now that the full revelation of God has been made, and the Holy Spirit has come, who searcheth all things, yea, the deep things of God, we can go back, as led and taught of Him, and discover much that could not before have been understood. It is one of the perils of the present moment that the Old Testament scriptures are being limited to the light possessed at the time they were given. The truth is, that their latent meaning can only be apprehended when looking back upon them from the full shining of the light of Christianity. There is no incongruity whatever, therefore, in affirming that God chose the special word Elohim to express the truth of the Trinity. For example, we read in Genesis that God created the heaven and the earth; and in John's gospel it is said of the Word, the Word who afterwards became flesh, "All things were made by Him; and without Him was not anything made that was made." We know consequently that the eternal Son is comprised in the word 'God' in Genesis, and as we ponder upon it we learn more of the glory of the person of our Redeemer.

It is quite true that this could not be comprehended at the time. It was not indeed until the baptism of our blessed Lord that the whole truth of the Trinity came out. Then God spake from heaven; His beloved Son was on the earth; and the Holy Ghost descended and abode upon the Son. But now that the full revelation of God has been made, and the Holy Spirit has come, who searcheth all things, yea, the deep things of God, we can go back, as led and taught of Him, and discover much that could not have been before understood. It is one of the perils of the present moment that the Old Testament scriptures are being limited to the light possessed at the time they were given. The truth is, that their latent meaning can only be apprehended when looking back upon them from the full shining of the light of Christianity. There is no incongruity whatever, therefore, in affirming that God chose the special word Elohim to express the truth of the Trinity. For example, we read in Genesis that God created the heaven and the earth; and in John's gospel it is said of the Word, the Word that afterwards became flesh, "All things were made by Him; and without Him was not anything made that was made." We know consequently that the eternal Son is comprised in the word 'God' in Genesis, and as we ponder upon it we learn more of the glory of the person of our Redeemer.

God the Son. Similarly, the Son is of course revealed, not merely in His human nature, nor as God incarnate, but back of that we have clear intimations of the eternal relationship between the Father and the only begotten Son who was in the bosom of the Father (John 1:18). The doctrine of the incarnation, we need hardly say, is on every page of the Gospels. We will examine this more in detail later. Our object just now is to trace the doctrine of the Trinity.

It is not the manner of Scripture to give proof-texts in the bare, literal way that men naturally crave. It would seem as though the Spirit of God purposely avoided this for as we have said, the knowledge of God is not an intellectual, but a moral perception. Of course the intellect is involved, but much more is necessary. Therefore we find nothing of a formal character, as though the doctrine were introduced for the sake of making orthodox statements. There is the most absolute freedom and absence of restraint in the narrative of the Gospels. All flows along with a simplicity and clearness, with a fervor and a depth which mark it as the work of God. There are, however, passages where the fulness of the Godhead shines out in an unmistakable way. Thus, at our Lord's baptism, significantly at the very time when He takes the lowliest place in anticipation of the cross where He goes for His people's sin, we have a glimpse of the Trinity. The Son is before us; His true glory veiled but not dimmed by His tabernacle of flesh. The heavens are opened and the Holy Spirit descends as a dove upon Him, while the Father's voice from that heavenly glory proclaims His beloved Son. Thus, Father, Son and Spirit are alike revealed.

The business of the Old Testament is to reveal the unity of the Godhead; the business of the New Testament is to reveal the Trinity; and therefore, though you have got at the beginning "the Spirit of God moved on the face of the waters" and elsewhere, it is not so clear in the Old Testament; there is no personal coming; As to the word "person," use what word may be best, but the testimony of scripture is plain enough that what we mean by a person is said both of the Father and of the Son and of the Holy Ghost.

In the Old Testament, the nation of Israel was taught the unity of Jehovah, their God (Deut. 6:4); in the Christianity of the New Testament, we have revealed to us the Trinity of the Godhead, the "name" of the three Persons to be confessed in baptism (Matt. 28:19). Not only did the Son come forth from the Father Who sent Him, but the Spirit proceeded from the Father, and was sent by the Father and the Son (John 15:26; 14:26).

In the Old Testament, the nation of Israel was taught the unity of Jehovah, their God (Deut. 6:4); in the Christianity of the New Testament, we have revealed to us the Trinity of the Godhead, the "name" of the three Persons to be confessed in baptism (Matt. 28:19). Not only did the Son come forth from the Father Who sent Him, but the Spirit proceeded from the Father, and was sent by the Father and the Son (John 15:26; John 14:26).

Thus we see that there could be no full revelation of God, but through the Son by the Spirit, and thereby of the Father. The full revelation of the one God is only thus - Father, Son, and Holy Ghost. This, this only, is what the one God is, one identity of will and being, so that they are essentially one and one only, yet distinct in willing and acting (and we can distinguish them in willing and acting: hence we commonly speak of persons), yet never willing or acting but in the common will and unity of nature.

I learn from the scriptures that there is one living God,1 fully revealed to us in Christ,2 and known through Him as Father, Son, and Holy Ghost,3 in the unity of the Godhead, but revealed as distinctively willing,5 acting,6 sending, sent,7 coming,8 distributing,9 and other actings; or, as habitually expressed amongst Christians, three persons in one God, or Trinity in Unity. God is the Creator of all things; but the act of creating is personally attributed to the Word and the Son, and the operation of the Spirit of God.10

The chapter opens with GOD. The word used in the Hebrew is Elohim, a word, remarkably enough, of plural form. This is the more striking when we remember that the Hebrew has, besides a singular, a dual form for its nouns. Dual signifies two, plural therefore signifying three or more. Yet the verb "created" is in the singular! Why this apparent breach of grammar? Evidently in order that in the very introduction to our knowledge of God we may receive a hint of the truth afterwards plainly revealed that He is a Trinity in Unity — three Persons yet one God. We have only to read verse 2 to discover mention of the Spirit of God, and later in the New Testament we find the active work of creation consistently attributed to the Lord Jesus, the Son. "His Son … by whom also He made the worlds" (Heb. 1:2). The first verse of the Bible, therefore, contains a denial of Unitarianism.