Trying to Understand the Trinity (Part 3): There is One God -

Trying to Understand the Trinity

Where Are We in the Series?

The doctrine of the Trinity brings together three biblical truths:

The Father, Son, and Holy Spirit are distinct persons.
Each person is fully God.
There is only one God.

Part 1: Three Distinct Persons — The Father is not the Son, the Son is not the Spirit, and the Spirit is not the Father.

Part 2: Each Person Is Fully God — Scripture identifies the Father, Son, and Holy Spirit as fully divine.

Part 3: There Is One God — You are here.

Bonus: The Trinity Is Not Like ______ — Why common illustrations for the Trinity often create more problems than they solve.

Quick Answer

The Bible teaches that there is only one God.

Christianity does not teach that the Father, Son, and Holy Spirit are three separate gods. Scripture consistently affirms monotheism while also identifying the Father, Son, and Holy Spirit as distinct persons who are fully divine.

Historic Christianity summarizes those biblical truths by saying that God is one in being or essence and three in person.

There are three distinct persons, each person is fully God, and yet there is only one God.

That may stretch our understanding, but it is not the same as saying that three Gods somehow equal one God.

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Does the Trinity Mean Christians Worship Three Gods?

If you’ve followed this series from the beginning, you may see the problem we’re trying to solve.

In Part 1 , we saw that the Father, Son, and Holy Spirit are distinct persons.

Then, in Part 2 , we looked at the biblical evidence that:

the Father is God,
the Son is God, and
the Holy Spirit is God.

So it is perfectly reasonable to ask:

If three distinct persons are each fully God, doesn’t that mean there are three Gods?

That would be the conclusion if Scripture presented Father, Son, and Spirit as three separate divine beings.

But Scripture never gives us that option.

The same Bible that identifies the Father, Son, and Holy Spirit as divine repeatedly insists that there is only one God.

Christianity is not tritheistic—belief in three gods. It is monotheistic.

And that conviction did not begin in the New Testament.

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What Does Deuteronomy 6:4 Mean?

One of the foundational declarations of Israel’s faith is found in Deuteronomy 6:4.

This verse begins what Jewish tradition calls the Shema, named after the Hebrew word translated “hear” or “listen.”

Moses calls Israel to hear that the LORD is their God and that the LORD is one (Deuteronomy 6:4).

The next verse calls God’s people to respond by loving Him with all their heart, soul, and strength (Deuteronomy 6:5).

Israel was not called to worship one God among many possible gods. The LORD alone was their God, and their allegiance belonged entirely to Him.

This conviction sits at the heart of biblical faith.

There is one God.

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Does the Rest of the Old Testament Teach That There Is One God?

Yes. Deuteronomy 6 is far from an isolated statement.

Israel’s Scriptures repeatedly emphasize the uniqueness of the LORD.

Solomon Declared That There Is No Other God

When Solomon dedicated the Temple in Jerusalem, he prayed that people throughout the earth would come to know that the LORD is God and there is no other (1 Kings 8:60).

Solomon’s prayer assumes more than Israel’s loyalty to a particular national deity.

His desire is that all the earth recognize the LORD as the only God.

The Old Testament’s claim is not:

“Israel worships Yahweh while other nations have their own equally real gods.”

Its claim is much bigger:

The LORD is God. There is no other.

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What Does God Say About Himself in Isaiah?

Some of the strongest statements about God’s uniqueness appear in Isaiah.

In Isaiah 45:5–6, the LORD repeatedly declares that He is the LORD and there is no other God.

A few verses later, God challenges the nations to consider who foretold these things and then declares that there is no other God besides Him (Isaiah 45:21).

He then calls people from the ends of the earth to turn to Him and be saved because He alone is God (Isaiah 45:22).

The Bible does not leave room for three independent Gods. The LORD Himself declares that there is no other God besides Him.

Similar declarations appear throughout this section of Isaiah:

Isaiah 43:10–11 — the LORD declares that no God existed before Him or will exist after Him.
Isaiah 44:6 — the LORD declares that besides Him there is no God.
Isaiah 44:8 — God asks whether there is any other God and answers in the negative.
Isaiah 45:18 — the Creator declares that He is the LORD and there is no other.

Biblical monotheism could hardly be stated more strongly.

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Does the New Testament Still Teach That There Is Only One God?

Absolutely.

The coming of Jesus does not cause the New Testament writers to abandon Israel’s belief in one God.

Instead, they continue to affirm it.

Jesus Affirmed Israel’s Confession of One God

When Jesus was asked which commandment was most important, He began His answer by quoting the Shema from Deuteronomy 6:4–5 (Mark 12:28–30).

Jesus affirmed the confession that the Lord is one.

Paul Taught That There Is One God

Paul says plainly that God is one (Romans 3:30).

In 1 Timothy 2:5, he teaches that there is one God and one mediator between God and humanity, Jesus Christ.

First Corinthians 8:4 likewise says that there is no God except one.

James Taught That There Is One God

James 2:19 assumes the same basic confession: there is one God.

James’ point is actually that simply agreeing with this truth intellectually is not enough—even demons know it.

Old Testament and New Testament agree: there is only one God.

This means Christians cannot solve the mystery of the Trinity by simply saying that Father, Son, and Spirit are three Gods.

Scripture will not allow us to do that.

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So How Can God Be One and Three?

Here is where careful language matters.

Christians do not believe that God is one person and three persons.

Nor do Christians believe that God is one God and three Gods.

Either statement would be contradictory.

Instead, historic Christianity makes a distinction between God’s being and God’s persons.

God is one in being or essence.

God eternally exists as three distinct persons: Father, Son, and Holy Spirit.

Another simple way of expressing the distinction is:

What is God?
One divine Being.

Who is God?
Father, Son, and Holy Spirit.

This language does not explain away the mystery.

It simply helps us say accurately what Scripture reveals without confusing the categories.

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Is the Trinity a Contradiction?

Sometimes people dismiss the Trinity by saying:

“You believe three equals one.”

But that is not actually what the doctrine teaches.

A contradiction would be saying that God is one person and three persons in the same sense at the same time.

Or that God is one being and three beings in the same sense at the same time.

Christianity says neither.

God is one in one sense—His being—and three in another sense—His persons.

That is certainly mysterious.

But mystery and contradiction are not the same thing.

A finite mind may not be able to comprehend exhaustively how the infinite God exists, while still being able to understand truly what He has revealed about Himself.

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Do the Father, Son, and Holy Spirit Work Together?

Yes.

Because there is one God, the persons of the Trinity do not operate as three competing divine beings with separate agendas.

Scripture repeatedly shows Father, Son, and Spirit working inseparably in God’s purposes.

Creation

Scripture attributes creation to God while also describing the Son and Spirit as active in creation (Genesis 1:1–2; John 1:1–3; Colossians 1:16).

The Incarnation

The Father sends the Son, and Jesus’ conception takes place through the Holy Spirit (Luke 1:35; Galatians 4:4).

Jesus’ Ministry

At Jesus’ baptism, the Son is baptized, the Spirit descends, and the Father speaks from heaven (Matthew 3:16–17).

Salvation

The New Testament describes salvation in distinctly Trinitarian terms: the Father chooses and purposes, the Son accomplishes redemption, and the Spirit applies God’s saving work and makes believers holy (Ephesians 1:3–14; 1 Peter 1:2).

The persons of the Trinity are distinct, but they are never divided in purpose, nature, or divine will.

The Father, Son, and Holy Spirit eternally share the one divine nature and work in perfect harmony.

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Can We Fully Understand the Trinity?

Probably not—and that shouldn’t surprise us.

If God is infinite and we are finite, we should expect there to be truths about God’s nature that exceed our ability to completely comprehend.

That does not mean God has revealed nothing understandable about Himself.

We can truly know what He has revealed even if we cannot know Him exhaustively.

Scripture gives us boundaries:

There are not three Gods.
There is not one divine person wearing three different masks.
The Father, Son, and Spirit are not three pieces that combine to make God.
Each person is fully God.
The three persons are genuinely distinct.
There is only one God.

Our job is not to simplify God until He fits comfortably inside an illustration.

Our job is to allow Scripture to tell us who God is.

This is also why common Trinity illustrations can sometimes create more confusion than clarity. Water, eggs, shamrocks, and other comparisons usually explain one aspect of the doctrine while accidentally distorting another.

We look more closely at that problem in The Trinity Is Not Like ______ .

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Heart Check

After three articles, it would be easy to finish this study with a better theological definition but never move beyond the definition.

But the Trinity is not merely information about God.

This is who God is.

Consider:

Am I content to let God reveal Himself as He truly is, even when I cannot completely explain Him?
Has studying the Trinity increased my wonder and worship—or merely given me more theological vocabulary?
Do I recognize salvation as the gracious work of the Father, Son, and Holy Spirit?
Am I seeking not merely to understand more about God, but actually to know and enjoy Him?

Theology is at its best when greater knowledge of God leads us to greater love for God.

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Key Takeaway

The Bible teaches that there is one God who eternally exists as three distinct persons: Father, Son, and Holy Spirit.

The Father is God. The Son is God. The Holy Spirit is God. Yet the Father is not the Son, the Son is not the Spirit, and the Spirit is not the Father.

God is one in being and three in person. This is what Christians mean when we say that God is Trinity.

We may be able to define that truth more carefully than when we began, but that does not mean we can completely explain the mystery of God’s being.

Michael Reeves offers a helpful reminder in Delighting in the Trinity:

“The Trinity is not a problem to be solved, but a God to be enjoyed.”

Perhaps this series has answered some of your questions.

Perhaps it has given you a few new ones.

Either way, don’t let the mystery of the Trinity push you away from knowing God. Let it draw you deeper into Scripture and deeper into wonder at the God who has chosen to reveal Himself to us.

And as you know Him more, may you increasingly enjoy Him—the Father who loves, the Son who saves, and the Spirit who gives life.

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Explore the Complete Trinity Series

Part 1: Three Distinct Persons
Why the Father, Son, and Holy Spirit are genuinely distinct from one another.

Part 2: Each Person Is Fully God
The biblical evidence for the full deity of the Father, Son, and Holy Spirit.

Part 3: There Is One God
How Scripture’s insistence on one God fits with the full deity of three distinct persons.

Bonus: The Trinity Is Not Like ______
Why popular illustrations of the Trinity often fail—and how they can accidentally lead us toward ancient misunderstandings of God.

Keep Studying

To explore the Bible’s teaching about the oneness of God for yourself, spend some time with these passages:

Deuteronomy 6:4–9 — Israel’s foundational confession that the LORD is one.
1 Kings 8:54–61 — Solomon declares that the LORD is God and there is no other.
Isaiah 43:10–13 — the LORD declares His uniqueness.
Isaiah 44:6–8 — there is no God besides the LORD.
Isaiah 45:5–22 — the Creator and Savior declares that He alone is God.
Mark 12:28–34 — Jesus affirms the Shema.
Romans 3:29–30 — Paul declares that God is one.
1 Corinthians 8:4–6 — Paul affirms one God while speaking of the Father and Jesus Christ.
1 Timothy 2:5–6 — one God and one mediator.
James 2:19 — even demons know that God is one.

One more step: Why Water, Eggs, and Other Popular Illustrations Don’t Quite Explain the Trinity

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Trying to Understand the Trinity (Part 3): There is One God