By Hubert Agamasu

Let me start with something we often forget in conversations between Christians and Muslims: both of us claim to believe in the God of Abraham. We both believe He created the heavens and the earth. We both revere Moses, the prophets, and believe in divine revelation. But where we differ dramatically is on the question of Jesus: who He is, and whether He is God.

This is not just a theological debate for me. In my experience teaching the Bible and discussing with Muslim friends, the issue of Jesus’ identity is always central. Some Muslims tell me, “Jesus never claimed to be God,” or, “The Trinity is a later invention.” But let’s be honest: have we really searched the Scriptures?

A defense of the Trinity:

Let’s begin here:

• Premise 1: The Bible is reliable. (We’ll explore this more deeply later.)

• Premise 2: The Bible teaches that God is a Trinity.

• Conclusion: Then God is a Trinity.

Now, before we throw our hands up about the Trinity being “illogical,” ask yourself: is God supposed to be simple? Can the Creator of the universe be compressed into one line of human logic? I don’t think so. The Bible doesn’t present God as a puzzle to solve, but as a Person to know—in fact, Three Persons.

Moses Wrote About Jesus

Jesus once told the Jews, “If you believed Moses, you would believe Me, for he wrote about Me” (John 5:46-47). That statement still stuns me. The Jews believed in the promised prophet of Deuteronomy 18:15-18—they were even expecting him (see John 1:21). So what did they miss?

What Moses wrote, again and again, was of a God who walked among men. This wasn’t a distant deity. He was the One who visited Abraham, dined with him (Genesis 18), wrestled with Jacob (Genesis 32), and led Israel through the wilderness. That Person was Christ before He took on flesh.

The Trinity in the Old Testament? Yes, It’s There!

Take Isaiah 48:12-16. The Speaker claims to be the First and the Last—the Creator of the heavens and the earth. That’s language used only for God. But here’s the twist: this Speaker says, “The Lord God and His Spirit have sent Me.”

Did you catch that?

• The Speaker is God (First and Last).

• Yet, He was sent by Yahweh and His Spirit.

• That makes three distinct persons.

This is not New Testament theology smuggled into the Old. This is the God of Israel revealing His nature. And I find it so compelling because it’s not forced; it’s already there. You just have to pay attention.

Another clear passage is Isaiah 63:7–14. It recounts how God saved Israel:

• Yahweh showed lovingkindness.

• The Angel of His Presence saved them (v.9).

• The Holy Spirit gave them rest (v.14) — but was also grieved when they rebelled (v.10).

This isn’t poetry; it’s theology. Yahweh, His Angel, and His Spirit are all active—yet united. That’s the Trinity before the New Testament ever mentions it.

Yahweh Sends Yahweh?

Let’s keep going. Zechariah 2:8-11 has a fascinating line: “Yahweh has sent Me to you” says… Yahweh. Yes, Yahweh says Yahweh sent Him. That’s not a typo. It’s divine dialogue. It only makes sense in a Trinitarian framework. Add in Isaiah 48 again, and you see:

• Yahweh speaks.

• Yahweh sends Yahweh.

• Yahweh sends Yahweh and His Spirit.

You know what that means? Any one of these three is Yahweh.

Who Is the Angel of the LORD?

This Angel of Yahweh isn’t your regular messenger. He is called God (Genesis 16:10,13). He wrestles Jacob and is identified as God by Jacob (Genesis 32:28-30, Hosea 12:4). He speaks in the first person as the God who delivered Israel from Egypt (Judges 2:1).

There’s more:

• He is called God by Hagar (Genesis 16:10,13)

• He is called God by Isaac (Genesis 48:15-16)

• He identifies himself to Jacob as God (Genesis 31:11-13)

• He is called God by God (Genesis 35:1)

• He bears God’s name (Exodus 23:20, compare Isaiah 63:9-10)

• He claims He brought Israel out of Egypt and made its covenant (Judges 2:1)

• He is identified as God by Gideon (Judges 6:22-23)

• He is identified as God by Samson’s parents (Judges 13:17-23)

• He forgives sins (Zechariah 3:1-2)

• He claims to be the appearance of YHWH

Now here’s a question: How can this Angel be God when the Bible says no one can see God and live? (Exodus 33:20). And yet, people see this Angel. What gives?

John 1:18 gives the answer: “No one has seen God at any time, but the only begotten God, who is in the bosom of the Father, He has made Him known.” The Son reveals the unseen God. That Angel was the pre-incarnate Christ.

The Word Is a Person

Sometimes people think “Word of God” just means “God’s speech” or “message.” But have you read 1 Samuel 15:10 or Genesis 15:1? The Word comes to people as a person.

John wasn’t being creative when he wrote, “In the beginning was the Word, and the Word was with God, and the Word was God… and the Word became flesh” (John 1:1,14). He was building on the Old Testament.

I love how Greek scholar Dan Wallace puts it: “What God was, the Word was.” In other words, Jesus was distinct in person, but equal in nature. One Being, three Persons.

What About the Holy Spirit?

The Spirit isn’t an “it.” The Spirit grieves (Ephesians 4:30), speaks (Acts 13:2), and creates (Job 33:4). He is God.

Isaiah 48 again shows all Three:

• Yahweh (the Sender)

• His Spirit (also Sender)

• The Sent One (also God)

Jesus later confirms this in Matthew 28:19: “baptizing them in the name (singular) of the Father, Son, and Holy Spirit.”

God Says “Us”

Why does God say, “Let Us make man in Our image” (Genesis 1:26)? Is He talking to angels? That doesn’t work. Angels don’t create. God alone creates.

Genesis 11:7: “Let Us go down.”

Genesis 3:22: “Man has become like one of Us.”

These plural pronouns reflect plurality in unity.

Our God Is One (Ehad)

Deuteronomy 6:4 contains a profound proclamation of the oneness of God: “Shema Yisrael, YHWH Eloheenu, YHWH Ehad! (Hear oh Israel, the Lord our God, The Lord is One)”.

There are two words that denote “one” in Hebrew: Yachid and Ehad.

• Yachid literally means singular/only, as we see in Jeremiah 6:26: “Mourn as for an only (Yachid) child.”

• Ehad, on the other hand, means oneness in unity. We see this in:
  • Genesis 2:24 – “…they become one (Ehad) flesh.”

  • Genesis 11:6 – “…the people have become as one (Ehad).”

Ehad denotes unity, not absolute singularity.

Mark 12:29 also uses Heis in Greek (oneness in unity), not Monos (singular only).

Only God Saves

Isaiah 43:11 is bold: “I, even I, am the Lord, and apart from Me there is no savior.”

Then you get to Titus 2:13: “Our great God and Savior, Jesus Christ.”

And 2 Peter 1:1: “Our God and Savior Jesus Christ.”

Not a contradiction. It’s because Jesus is that God who saves. That’s why Thomas looked at Him and said, “My Lord and My God.”

Why God Had to Die for Us

Let’s wrap this up with why this matters.

In Leviticus 17:11, God said the life of the flesh is in the blood, and He gave it on the altar to make atonement. That’s serious. Only a perfect sacrifice could take away sin.

Jesus was that sacrifice. The Lamb of God.

But to pay for eternal punishment for billions of sinners, you need more than a good man. You need God Himself. That’s the gospel.

Look, I know the Trinity sounds complicated. But God isn’t a math equation. He is a divine community of love: Father, Son, and Spirit.

So here’s my question to you, whether you’re a Christian looking to grow deeper, or a Muslim friend honestly seeking:

If the Scriptures show that Yahweh walked among us, forgave sins, received worship, died for our sins, and rose again—is that not Jesus?