What Is the Trinity? One God in Three Persons

Most people have heard that Christians believe in the Trinity. Fewer could explain it, and it is one of the first things people ask about when they look at the Christian faith.

The difficulty is real, and it is worth stating before we try to answer it.

The Bible insists that there is only one God. Then it calls the Father God, and the Son God, and the Holy Spirit God. Those two things have to be held together, and the Trinity is the church’s attempt to hold them.

Let’s take it one piece at a time.

God Is One

Start where Israel started.

Deuteronomy 6:4 (NIV) — “Hear, O Israel: The Lord our God, the Lord is one.”

This is called the Shema, from the first Hebrew word, hear. Jewish people recited it every morning and every evening. Children learned it before they could read.

And when Jesus was asked which commandment was the greatest, He began with this one (Mark 12:29).

Isaiah says it just as firmly:

Isaiah 44:6 (NIV) — “I am the first and I am the last; apart from me there is no God.”

Isaiah 45:5 (NIV) — “I am the Lord, and there is no other; apart from me there is no God.”

There is no room in those verses for a second God. Whatever the Trinity means, it cannot mean three Gods.

Hold on to that, because everything else has to fit inside it.

The Old Testament Was Not Simple Either

People often assume this all begins with Jesus. It doesn’t. The Hebrew Scriptures already had passages that were hard to square with one single person.

Daniel is shown God’s throne room. The figure seated on it is called the Ancient of Days. Then a second figure comes into the scene, and Daniel watches what happens to Him:

Daniel 7:13-14 (NIV) — “there before me was one like a son of man, coming with the clouds of heaven. He approached the Ancient of Days and was led into his presence. He was given authority, glory and sovereign power; all peoples, nations and languages worshiped him.”

One figure is God on His throne. Another comes to Him, and receives worship.

That should stop a Jewish reader. Worship belongs to God alone.

Then there is a line from David that Jesus Himself used:

Psalm 110:1 (NIV) — “The Lord says to my Lord: ‘Sit at my right hand until I make your enemies a footstool for your feet.'”

David is writing, and he calls someone else my Lord — someone who sits at God’s right hand.

Jesus put that verse to the Pharisees Himself. He asked them whose son the Messiah would be, and they answered: David’s son. Then He asked this:

Matthew 22:45 (NIV) — “If then David calls him ‘Lord,’ how can he be his son?”

Matthew 22:46 (NIV) — “No one could say a word in reply, and from that day on no one dared to ask him any more questions.”

These passages do not spell out the Trinity. But they show that the Old Testament already had more than one figure who was treated as God.

The Father Is God

Nobody disputes this one, so we can be brief.

1 Corinthians 8:6 (NIV) — “yet for us there is but one God, the Father, from whom all things came and for whom we live; and there is but one Lord, Jesus Christ, through whom all things came and through whom we live.”

Jesus prayed to Him, taught us to call Him Father, and said He was doing His will. That much is clear throughout the New Testament.

But notice what Paul does in that verse. He says there is one God, the Father — and in the same breath he says there is one Lord, Jesus Christ, and gives Him the same role in creation.

The Son Is God

Start with how John opens his Gospel:

John 1:1 (NIV) — “In the beginning was the Word, and the Word was with God, and the Word was God.”

Read that carefully. The Word was with God — so He is distinct from the Father. And the Word was God — so He is not a lesser being.

Then John tells us who the Word is:

John 1:14 (NIV) — “The Word became flesh and made his dwelling among us.”

There is also a place where the Father speaks about the Son and calls Him God:

Hebrews 1:8 (NIV) — “But about the Son he says, ‘Your throne, O God, will last for ever and ever.'”

That is God the Father, addressing the Son as God.

And there is the title we saw earlier. God said in Isaiah that He alone is the First and the Last, and that there is no God besides Him. Then the risen Jesus says this:

Revelation 1:17-18 (NIV) — “Do not be afraid. I am the First and the Last. I am the Living One; I was dead, and now look, I am alive for ever and ever!”

Revelation 22:13 (NIV) — “I am the Alpha and the Omega, the First and the Last, the Beginning and the End.”

God said that title belongs to Him alone. Jesus takes it for Himself.

The Spirit Is God

The clearest passage is a story in Acts.

A man named Ananias sold some property, kept back part of the money, and pretended he had given all of it. Peter confronted him:

Acts 5:3-4 (NIV) — “Ananias, how is it that Satan has so filled your heart that you have lied to the Holy Spirit…? You have not lied just to human beings but to God.”

Read those two sentences together. Peter says he lied to the Holy Spirit. Then he says he lied to God. Peter used the two names for the same person.

Paul also says something about the Spirit that could only be true of God:

1 Corinthians 2:10-11 (NIV) — “The Spirit searches all things, even the deep things of God… no one knows the thoughts of God except the Spirit of God.”

Only God knows the mind of God.

Is the Spirit a Person, or Just a Power?

This is where many people get stuck. It is easy to think of the Holy Spirit as a force — God’s power, or His influence, rather than someone.

But look at what Scripture says He does.

He teaches and reminds:

John 14:26 (NIV) — “the Holy Spirit, whom the Father will send in my name, will teach you all things and will remind you of everything I have said to you.”

He speaks, and He makes decisions:

Acts 13:2 (NIV) — “the Holy Spirit said, ‘Set apart for me Barnabas and Saul for the work to which I have called them.'”

He chooses:

1 Corinthians 12:11 (NIV) — “he distributes them to each one, just as he determines.”

And He can be grieved:

Ephesians 4:30 (NIV) — “And do not grieve the Holy Spirit of God, with whom you were sealed for the day of redemption.”

Now think about what it would mean if the Holy Spirit were only God’s power.

You cannot grieve electricity. It has nothing to hurt. And Ananias could not have lied to a power, because lying needs someone on the other end who can be deceived.

Yet Scripture says the Spirit is grieved, and that Ananias lied to Him. Those things only happen between persons.

So the Holy Spirit is not something God sends. He is someone God sends. He can be lied to, grieved, and ignored, the way a person can.

Jesus also used personal language for Him. He called the Spirit “another Helper” (John 14:16) — another one like Himself.

All Three Together

So far we have looked at the three separately. But there is one scene where all three appear at once.

Jesus is baptised in the Jordan:

Matthew 3:16-17 (NIV) — “As soon as Jesus was baptized, he went up out of the water. At that moment heaven was opened, and he saw the Spirit of God descending like a dove and alighting on him. And a voice from heaven said, ‘This is my Son, whom I love; with him I am well pleased.'”

Look at what is happening in that moment.

The Son is standing in the water. The Spirit is descending on Him. The Father is speaking from heaven.

All three at the same time, and each one distinct from the other two.

Jesus also put the three names together when He sent out His disciples:

Matthew 28:19 (NIV) — “go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit.”

Notice that He says name, not names. Three persons, one name.

Paul ends a letter the same way:

2 Corinthians 13:14 (NIV) — “May the grace of the Lord Jesus Christ, and the love of God, and the fellowship of the Holy Spirit be with you all.”

Where the Word Came From

The word Trinity is not in the Bible, and there is no point pretending otherwise.

It comes from the Latin trinitas. As far as we know, it was first used by a writer named Tertullian around AD 200, roughly a century and a half after the New Testament was written.

But the word was not inventing something new. It was giving a name to something the Bible already showed. The church needed a short way to say: one God, three persons, all fully God, none of them the same as the other.

Plenty of words Christians use every day are like this. Incarnation is not in the Bible. Neither is omnipresent, or monotheism, or rapture, or original sin. Each one is a short label for something Scripture describes at length. The Bible never uses the word Bible either.

And it is not only the word that is missing. No single verse states the doctrine either.

Not one passage says “God is three persons in one being.” What we have instead is a set of statements that have to be held together.

God is one. The Father is God. The Son is God. The Spirit is God. And the three are not the same as each other.

The Bible gives us the pieces. The Trinity is what happens when you put them together.

That is worth saying plainly, because sooner or later someone will tell you the Trinity isn’t in the Bible. They are half right. The word isn’t, and neither is a single verse that spells it out. What is there is everything the doctrine is built from.

There is also a verse you may have seen quoted that should not be used. Older King James Bibles include this at 1 John 5:7:

1 John 5:7 (KJV) — “For there are three that bear record in heaven, the Father, the Word, and the Holy Ghost: and these three are one.”

It looks like the perfect proof text. But it is not part of the original letter. It does not appear in any Greek manuscript before the sixteenth century, and modern translations leave it out or move it to a footnote.

It is better to know that than to be shown it later by someone who does.

The case for the Trinity does not rest on one verse. It rests on the whole pattern — and the pattern is there whether or not that sentence is.

What the Trinity Is Not

Three wrong pictures are common, and naming them helps.

It is not three Gods. That would break Deuteronomy 6:4 and everything Isaiah said. Christians do not worship three beings who cooperate. There is one God.

It is not one God wearing three masks. Some imagine God switching roles — Father in the Old Testament, Son on earth, Spirit afterwards. But go back to the baptism. The Son is in the water while the Spirit descends while the Father speaks. He is not changing costumes. All three are there at once.

Daniel saw the same thing centuries earlier. The son of man does not become the Ancient of Days. He walks up to Him.

It is not a ranking. The Son is not a lesser God, and the Spirit is not a junior one. Scripture calls all three God without putting them in order.

People often reach for pictures to explain this. Water that can be liquid, ice, or steam. The sun, its light, and its heat.

Both of them break. Water is usually one thing at a time, which is the second mistake above. And light and heat come out of the sun. They are things it produces, not the sun itself.

That is worth noticing. It is not that we haven’t found the right picture yet. There isn’t one.

Everything we could compare God to is something He made. And nothing He made is like Him in this.

So we are left describing something we did not invent and cannot fully take in, which is roughly what we should expect when talking about God.

That is not a weakness in the doctrine. If God could be summed up in an illustration, He would be smaller than we are.

Why It Matters

This is not just a doctrine to agree with. It changes how we see the way God has come to us.

In the Old Testament, God spoke to His people through prophets, and His Spirit came upon particular people for particular tasks. There was distance in it.

Then the Son came and lived among us — God, in a body, close enough to touch.

And when He was leaving, He said this:

John 16:7 (NIV) — “It is for your good that I am going away. Unless I go away, the Advocate will not come to you; but if I go, I will send him to you.”

Better for them that He leave? Only because of what came next. Jesus had already told them the Spirit would not just be with them but in them (John 14:17).

Romans 8:9 (NIV) — “You, however, are not in the realm of the flesh but are in the realm of the Spirit, if indeed the Spirit of God lives in you.”

God went from speaking to His people through prophets to living inside them.

So the Father planned it, the Son accomplished it, and the Spirit applies it to us. Three persons, one God, one work of salvation.

That is not a riddle to be solved. It is how God has drawn near.

Last updated 9 September 2026