FROM “THE WAY” TO THE WHOLE WORLD

How Did a Jewish Movement Become Christianity?

Today Judaism and Christianity are plainly different religions.

But open the book of Acts and the distinction is not nearly so obvious.

Jesus was Jewish.

The apostles were Jewish.

The first believers were Jewish.

The church began in Jerusalem.

The first Christians read Israel's Scriptures, worshiped Israel's God, and proclaimed that Israel's promised Messiah had come.

So how did this movement centered in Jerusalem become a worldwide community of Jews and Gentiles known as Christians?

It did not happen socially overnight.

Acts allows us to watch it happen.

Something Had Already Changed

Before following Saul's story, we need to distinguish between what God had accomplished and how quickly people understood it.

When Jesus died, Matthew tells us:

“The curtain of the temple was torn in two, from top to bottom.”
— Matthew 27:51

That was not something human beings did from the bottom upward.

Something had changed.

Hebrews later explains the theological significance of Christ's sacrifice. Jesus entered the true holy place with His own blood and obtained eternal redemption (Hebrews 9:11–12). His sacrifice was offered “once for all” (Hebrews 10:10).

The old covenant was passing away. Hebrews says:

“In speaking of a new covenant, he makes the first one obsolete.”
— Hebrews 8:13

So from the standpoint of God's redemptive work, the decisive change had occurred.

Christ had offered the sacrifice.

The veil had been torn.

The new covenant had come.

But that does not mean everyone immediately understood what had happened.

Not even the believers did.

And that is the story Acts tells.

Saul Still Saw a Jewish Controversy

When Saul left for Damascus, he wasn't setting out to persecute what he understood to be a new Gentile religion called Christianity.

Acts says:

“Saul... went to the high priest and asked him for letters to the synagogues at Damascus.”
— Acts 9:1–2

Look at those words:

High priest.

Synagogues.

Jerusalem.

Saul intended to arrest people belonging to “the Way” and bring them back to Jerusalem.

Whatever the exact legal force of those letters outside Judea, Acts plainly presents this persecution within the Jewish religious world.

That makes sense.

At this stage the Jesus movement had grown out of Israel.

Saul thought these Jews were wrong about Israel's Messiah.

He believed he was defending the faith of his fathers.

Then something happened that destroyed Saul's basic assumption.

Saul Met the Messiah He Was Persecuting

On the Damascus road Jesus confronted him:

“Saul, Saul, why are you persecuting me?”
— Acts 9:4

Saul discovered that Jesus was alive.

Think what that meant for this highly educated Pharisee.

The Scriptures hadn't changed.

Saul's understanding of them had to change.

Jesus really was the Messiah.

Soon Saul was in the synagogues proclaiming Jesus as the Son of God and demonstrating that He was the Christ (Acts 9:20–22).

But Saul did not immediately leave Damascus and begin the missionary journeys we associate with Paul.

There were years in between.

The Missing Years Matter

Paul later tells us that he went into Arabia, returned to Damascus, and after three years went to Jerusalem (Galatians 1:15–18).

Eventually he went into the regions of Syria and Cilicia (Galatians 1:21).

Acts tells us he was sent to his hometown of Tarsus (Acts 9:30).

Then Saul largely disappears from Luke's account for several years.

Scripture does not tell us everything he did during that period, so we shouldn't pretend that it does.

We know he was already preaching Christ.

But we also know what Saul brought into those years.

He had been thoroughly trained in Israel's Scriptures. He had studied under Gamaliel (Acts 22:3). Paul says he had advanced in Judaism beyond many of his contemporaries (Galatians 1:14).

Now he knew that the crucified Jesus was alive.

Whatever else happened during those years, Saul's understanding of Israel's Scriptures now had to reckon with that fact.

And while Saul was away, God was teaching Peter something equally revolutionary.

God Opened the Door Through Peter

Acts 10 is one of the great turning points.

God sent Peter to Cornelius, an uncircumcised Gentile.

Peter himself needed convincing.

When he finally entered Cornelius's house, Peter said:

“Truly I understand that God shows no partiality.”
— Acts 10:34

Then something happened that astonished Peter's Jewish companions.

The Holy Spirit was poured out upon the Gentiles.

Acts says:

“The believers from among the circumcised who had come with Peter were amazed.”
— Acts 10:45

Why amazed?

Because God was doing something they had not expected.

Gentiles were receiving God's blessing as Gentiles.

Even Christians Had to Learn What God Was Doing

When Peter returned to Jerusalem, other believers criticized him:

“You went to uncircumcised men and ate with them.”
— Acts 11:3

Peter explained what had happened.

Then he asked:

“Who was I that I could stand in God's way?”
— Acts 11:17

Finally they acknowledged:

“Then to the Gentiles also God has granted repentance that leads to life.”
— Acts 11:18

Notice the progression.

God had acted.

Then Peter understood.

Then Peter explained it.

Then the Jerusalem believers understood.

The truth was not changing.

Their understanding was.

That pattern will continue throughout Acts.

Then Came Antioch

The next development occurs at Antioch of Syria.

Luke tells us that some scattered believers had originally spoken the word:

“to no one except Jews.”
— Acts 11:19

But others began proclaiming Jesus to Gentiles.

Many believed.

Jerusalem sent Barnabas to investigate.

Barnabas saw God's grace at work.

Then Barnabas did something important.

He went to Tarsus looking for Saul.

“And when he had found him, he brought him to Antioch.”
— Acts 11:26

For a year Barnabas and Saul taught this congregation.

And Luke tells us:

“In Antioch the disciples were first called Christians.”
— Acts 11:26

That doesn't mean Christianity suddenly became a completely separate religion throughout the Roman Empire that afternoon.

But something was becoming visible.

A community composed of people from different ethnic backgrounds was centered not upon their common Jewish ethnicity—

but upon Christ.

They were being called Christians.

Then Saul Becomes Known as Paul

Acts 13 marks another fascinating development.

The Holy Spirit tells the Antioch congregation:

“Set apart for me Barnabas and Saul for the work to which I have called them.”
— Acts 13:2

They are sent into the wider world.

Then Luke writes:

“Saul, who was also called Paul...”
— Acts 13:9

This was not a conversion name change.

He already possessed both names.

Saul was his Jewish name. Paul was his Roman name.

But from this point onward Luke normally calls him Paul.

Why does Luke begin using his Roman name precisely here?

Luke doesn't tell us.

So we should not turn our interpretation into a fact.

But the timing is certainly worth noticing.

The man who had once traveled under authority from the high priest to arrest followers of “the Way” was now moving increasingly into the Greco-Roman world.

He would eventually describe himself as:

“an apostle to the Gentiles.”
— Romans 11:13

A Roman name was entirely at home in the world in which Paul's great mission would now take place. This connection between Luke's switch to “Paul” and the increasingly Roman/Gentile environment has long been suggested, although the text itself gives no explanation of Paul's motive. (Reading Room)

Must Gentiles Become Jews?

Soon the church had to face the unavoidable question.

If Gentiles could believe in Israel's Messiah, must they become Jews?

Some Christians said yes:

“Unless you are circumcised according to the custom of Moses, you cannot be saved.”
— Acts 15:1

That was not a minor argument.

It went to the heart of what this growing movement was becoming.

Did a Gentile have to enter Judaism in order to belong to God's people?

The apostles and elders met in Jerusalem.

Peter reminded them of what God had already done with Cornelius.

Paul and Barnabas told what God had done among the Gentiles.

And the conclusion was clear:

Gentiles did not have to become Jews in order to belong to Christ.

But why?

Paul would spend much of his ministry explaining the answer.

Paul Went Back Before Moses

Paul didn't argue that God had tried Judaism, discovered it didn't work, and invented Christianity instead.

He went much farther back.

Before Moses.

Before Sinai.

Before the Law.

Paul went back to Abraham.

God had promised:

“In you all the families of the earth shall be blessed.”
— Genesis 12:3

Paul quotes that promise:

“In you shall all the nations be blessed.”
— Galatians 3:8

Then he makes a remarkable argument.

The Law came 430 years after God's promise to Abraham (Galatians 3:17).

Therefore the Law could not cancel the earlier promise.

God's purpose had always reached beyond one nation.

Israel had an indispensable role in that purpose.

Through Israel came the Messiah.

But the blessing promised through Abraham was intended for:

all nations.

Who, Then, Belongs to Abraham's Family?

Paul gives the answer:

“There is neither Jew nor Greek... for you are all one in Christ Jesus.”
— Galatians 3:28

Then:

“If you are Christ's, then you are Abraham's offspring, heirs according to promise.”
— Galatians 3:29

That is an enormous statement.

Gentiles did not have to become ethnic Jews.

Jewish believers did not have to become Gentiles.

Both belonged to Christ.

And because they belonged to Christ, they belonged to Abraham's promised family.

Paul develops the same idea in Ephesians.

Gentiles had once been:

“alienated from the commonwealth of Israel and strangers to the covenants of promise.”
— Ephesians 2:12

But Christ made Jew and Gentile one (Ephesians 2:14).

He created:

“one new man”
— Ephesians 2:15

Gentile Christians therefore were:

“no longer strangers and aliens, but... fellow citizens with the saints and members of the household of God.”
— Ephesians 2:19

Paul even closes Galatians with the striking expression:

“the Israel of God.”
— Galatians 6:16

Scholars disagree about precisely whom Paul means by that final expression, so we should not make our entire argument depend upon it.

We don't need to.

Paul's undisputed argument has already established the essential point:

Those who belong to Christ are Abraham's offspring and heirs of the promise.

Ethnicity no longer determines access to God's covenant family.

Christianity Was Not God's Plan B

This may be the most important point in the whole study.

Christianity did not become universal because Paul decided Judaism was too narrow.

Peter did not invent the Gentile mission.

Paul did not invent it.

The church at Antioch did not invent it.

God had promised it to Abraham.

Jesus had commanded it:

“You will be my witnesses in Jerusalem and in all Judea and Samaria, and to the end of the earth.”
— Acts 1:8

Now watch Acts unfold:

Jerusalem.

Judea.

Samaria.

Cornelius.

Antioch.

Asia Minor.

Greece.

Rome.

The gospel is moving exactly where Jesus said it would go.

But People Understood the Change Gradually

Here is where we must distinguish two things.

Theologically, the decisive work had already been accomplished in Christ.

But historically and socially, Jews, Christians and Roman authorities did not instantly understand all its implications.

We can see that inside Acts itself.

Gallio treats Paul's controversy at Corinth as a dispute involving Jewish words, names and law (Acts 18:12–17).

Years later Festus describes Paul's case as a controversy involving the Jews' own religion and:

“a certain Jesus, who was dead, but whom Paul asserted to be alive.”
— Acts 25:19

Agrippa and Festus ultimately conclude that Paul has done nothing deserving death or imprisonment (Acts 26:31).

So even relatively late in Paul's ministry, Roman authorities could encounter the Jesus movement through the framework of Jewish religious disputes.

Modern historical research reinforces the need for caution here. Scholars increasingly reject the idea that Judaism and Christianity separated everywhere at one identifiable moment. The boundaries developed differently in different places, and Jewish-Christian interaction continued for centuries. (OUP Academic)

That makes Acts more understandable, not less.

Eventually the Difference Became Impossible to Miss

By A.D. 64, after the great fire of Rome, the Roman historian Tacitus tells us that Nero targeted people known as Christians.

By then outsiders in Rome could identify Christians as a recognizable group associated with Christus, whom Tacitus says had been executed under Pontius Pilate.

That doesn't mean A.D. 64 was the official birthday of Christianity as a separate Roman religion.

It wasn't.

It simply shows how far the social identification had progressed.

Compare the two ends of our story.

Saul going to Damascus

High priest.
Synagogues.
Jerusalem.
“The Way.”

The controversy operates largely within the Jewish world.

Christianity spreading through the Roman world

Gentile congregations.
Paul's missions.
Jew and Gentile together.
The name “Christians.”

Something enormous had happened.

But socially, it happened gradually.

One Change—Understood Over Time

This may be the simplest way to put the whole story.

At the cross, God acted decisively.

Christ offered the once-for-all sacrifice.

The veil was torn.

The new covenant had come.

But people had to learn what God's action meant.

Saul had to learn.

Peter had to learn.

The Jerusalem believers had to learn.

The church had to settle the Gentile question.

Jewish communities had to respond to it.

Gentiles had to discover that Israel's Messiah was also their Savior.

Roman authorities gradually encountered an increasingly recognizable Christian community.

The gospel began in the Jewish world because God's promises had come through Israel.

But it could never remain an ethnically Jewish movement.

God had told Abraham where the story was going:

“In you all the families of the earth shall be blessed.”

And in Christ, Paul says, that promise reaches Jew and Gentile alike:

“If you are Christ's, then you are Abraham's offspring, heirs according to promise.”
— Galatians 3:29

The separation visible today between Judaism and Christianity did not appear overnight in human society. Historians continue to debate precisely how and when those boundaries hardened, and evidence indicates that the process was long and uneven. (Sage Journals)

But Acts lets us watch the beginning of the transformation.

From “the Way” in Jerusalem...

to Christians at Antioch...

to Jew and Gentile becoming one in Christ...

to the gospel reaching the Roman world.

And behind it all was a promise God had made long before:

All nations would be blessed through Abraham's Seed.

READ IT FOR YOURSELF

Acts 1:1–8
Acts 9:1–30
Acts 10:1–48
Acts 11:1–30
Acts 13:1–12
Acts 15:1–35
Acts 18:12–17
Acts 24–26
Galatians 3:6–29
Galatians 6:15–16
Ephesians 2:11–22
Hebrews 8–10

ONE QUESTION

Was the inclusion of the Gentiles a change in God's plan—or was it the fulfillment of the plan He had announced to Abraham from the beginning?

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