The doctrine of the Trinity is summarized by seven basic propositions:
1. The Father is God. (Phil. 1:2, Eph. 4:6)
2. The Son is God. (Col. 2:9, Phil. 1:2)
3. The Holy Spirit is God. (2 Cor. 3:17, Acts 5:3-4)
4. The Father is not the Son. (John 10:30, Phil. 2:9)
5. The Son is not the Spirit. (Matt. 28:19, John 20:22)
6. The Spirit is not the Father. (John 14:26, Gal. 4:6)
7. There is only one God. (1 Cor. 8:6, Rom. 1:21)
When it comes to the New Testament, this doctrine is proven easily enough; just look up the references above. But what of the Old Testament? Some accuse the early church fathers, such as Tertullian, of “inventing” the doctrine. Some even go so far as to accuse the New Testament authors, such as Paul, of doing the same. But is this unfair? Is this doctrine in fact to be found in the Old Testament?
According to Dr. Michael Brown, author of the “Answering Jewish Objections to Jesus” series of books, the answer is a resounding, “Yes!” In volume two of that series, he details how the Old Testament teaches how the doctrine of the Trinity.
So just how do we establish the doctrine from the OT? While the content of the doctrine is to be found there, the terminology changes from one testament to the other. Instead of the NT terminology of, “Father, Son, and Holy Spirit” the OT terminology is “the Lord, the Angel of the Lord, and Spirit of the Lord.” If I can show that the seven propositions are true, then I have also shown that these three names are referring to the three Persons of the Trinity.
Let’s start with Exodus 3. This is the famous “burning bush” passage. In 3:2, “the angel of the Lord appeared to [Moses] in a flame of fire out of the midst of a bush.” But later on, Moses himself says that the Lord appeared to him (v. 16) and the text itself says it was the Lord (v. 4). So Scripture identifies the angel of the Lord as the Lord.
(I should note at this point that, although the Old Testament speaks of “angels” or even “an angel of the Lord” the title “the angel of the Lord” with the definitive article is clearly a special being, and He is repeatedly identified as being the Lord.)
But the angel of the Lord is also distinguished as being separate from the Lord. 2 Sam. 24:16 says, “And when the angel stretched out his hand toward Jerusalem to destroy it, the Lord relented from the calamity and said to the angel who was working destruction among the people, ‘It is enough; now stay your hand.’ And the angel of the Lord was by the threshing floor of Araunah the Jebusite.” This passage clearly talks about the Lord and the angel of the Lord as if they are distinct beings.
So far, we have the angel of the Lord who is clearly identified as the Lord, and yet is separate from another divine being known as the Lord.
Now, let’s talk about the Spirit of the Lord. In 2 Sam. 23:1-2, David says, “The Spirit of the Lord speaks by me; his word is on my tongue. The God of Israel has spoken; the Rock of Israel has said to me: When one rules justly over men, ruling in the fear of God…” This is a typical Hebrew poetic couplet, in which an idea is restated in a second way. Thus, when David says, “The Spirit of the Lord speaks…” he restates this with, “The God of Israel has spoken…” So David clearly says that when the Spirit of the Lord speaks (v. 2) it is The Lord Himself speaking (v. 3). So the Spirit of the Lord is the Lord.
But the Spirit is also distinct from another divine being who is the Lord. Isaiah 63:11, “Then he remembered the days of old, of Moses and his people. Where is he who brought them up out of the sea with the shepherds of his flock? Where is he who put in the midst of them his Holy Spirit.” The “he” here is clearly the Lord, and yet the passage itself indicates a distinction between Him and His Holy Spirit.
Now we turn, finally, to Is. 48:16. First, let’s note that in context, it is the Lord who is speaking (48:13, 45:14). He says, “‘Draw near to me, hear this: from the beginning I have not spoken in secret, from the time it came to be I have been there.’ And now the Lord God has sent me, and his Spirit.” Notice that not only is the speaker The Lord, but He says that The Lord has sent Him and the Lord’s Spirit. So here we have three separate beings, two of which are explicitly identified as The Lord, and yet this is the same prophet who also says there is only one God (43:10, also see Deut. 6:4). This, combined with all other the other passages, clearly and explicitly teaches the doctrine of the Trinity.
So let’s summarize:
1. (The Father) is the Lord (Hos. 11:1)
2. The Angel of the Lord is the Lord (Ex. 3:3, 4, 16)
3. The Spirit of the Lord is the Lord (2 Sam. 23:1-2)
4. (The Father) is not the Angel of the Lord (2 Samuel 24:16)
5. The Angel of the Lord is not the Spirit of the Lord (Is. 48:16)
6. The Spirit of the Lord is not (the Father) (Is. 48:16, 63:11)
7. There is only one God (Is. 43:10, Deut. 6:4)
Thus, Trinitarian Christians can confidently assert that the doctrine of the Trinity was expressed in the OT itself, over against Jewish, Muslim, and Mormon detractors. It was not “invented” by Tertullian or the NT authors, but by the OT itself.
You can get your own copy of “Answering Jewish Objections to Jesus, vol. 2” at Amazon here.
Five questions I would like to ask Dr. Brown
1. Is there any difference in meaning between “the Lord” and “God”?
2. What history is there behind referring the second person as “The Word”?
3. Does the OT teach that the Angel of the Lord has anything to do with our salvation?
4. Does Jesus claim to specifically be the Angel of the Lord in John 8?
5. Is the commander of the army of the Lord the Angel of the Lord?