The Triunity in Isaiah
Bible-believing Christians hold fast to many cardinal doctrines of the faith, such as the virgin birth, inspiration of Scripture, substitutionary atonement, justification by faith, and the plurality within the Godhead (the Trinity). If you conducted a survey concerning these doctrines, you probably would find that most people think they come entirely from the New Testament. But all of them are contained in the book of Isaiah, including the doctrine of the Trinity.
Trinitarianism, as it is often called, simply means there is one Deity manifested or revealed through three distinct personalities. The word trinity can denote the number three or a group of three. Although much of Christendom uses Trinity to identify God the Father, Son, and Holy Spirit, the term triunity is slightly more accurate. It embraces the plurality yet identifies a stronger, consistent accord between the three Persons.
The doctrine of the Triunity is difficult to grasp even for Christians who have known the Lord for many years. Nothing compares to it, so it cannot be explained in human terms. There is only one God: the God of Abraham, Isaac, and Jacob. Yet He somehow exists in three Persons who are identical in substance and form the Godhead.
Isaiah alluded to the Triunity when he prophesied; but it is likely he, too, did not fully understand it.
In chapter 48 God says through the prophet, “Listen to Me, O Jacob, and Israel, My called: I am He, I am the First, I am also the Last. Indeed My hand has laid the foundation of the earth” (vv. 12–13). Clearly, the speaker is the God of Israel.
Then God says, “Come near to Me, hear this: I have not spoken in secret from the beginning; from the time that it was, I was there. And now the Lord Gᴏᴅ and His Spirit have sent Me” (v. 16).
If God is speaking, then who are “the Lord Gᴏᴅ” and “His Spirit” and “Me”? More confusing still is the fact the Lord God and the Holy Spirit sent the One who is called the First and the Last—the One who laid the foundation of the earth.
Clearly, all three of these entities are God. Isaiah unveiled all three Persons of the Godhead: “the Lord Gᴏᴅ,” referring to the Father; “His Spirit,” referring to the Holy Spirit; and “Me,” referring to the speaker, who later identifies Himself as the “Redeemer” (v. 17). Thus the speaker is the Messiah.
More than 700 years after Isaiah prophesied, Jesus was born as a Jewish baby in Bethlehem of Judea, fulfilling Micah 5:2 and many other Hebrew Scriptures. He performed miracles only God could do, including raising the dead, and admitted to being the Messiah (Mt. 26:63–64; Jn. 4:25–26).
Many years after His death and resurrection, He appeared in a vision to the apostle John, also Jewish, on the island of Patmos: “‘I am the Alpha and the Omega, the Beginning and the End,’ says the Lord, ‘who is and who was and who is to come, the Almighty’” (Rev. 1:8).
Paul, another Jewish apostle, educated believers at Colosse concerning Jesus, echoing Isaiah: “He is the image of the invisible God, the firstborn over all creation. For by Him all things were created that are in heaven and that are on earth” (Col. 1:15–16).
God exists in three Persons, yet there is only one God; and Bible-believing Christians who accept the Triunity worship only the God of Israel who spoke through the prophet Isaiah.