How the Christian Movement Managed to Take Over the World


By Bart D. EhrmanThe University of North Carolina, Chapel Hill

In many ways, for the future of the Christian movement, the ethnic spread of the faith was by far the most significant development within the early Christian tradition. The original followers of Jesus were Jewish, just as he was. They believed that Jesus was the Jewish messiah, sent from the Jewish God to the Jewish people in fulfillment of the Jewish law. Faith in Jesus was a Jewish faith.

Image of a cross with sunlight in the background
At its earliest, the Christian movement was seen as a Jewish one. (Image: Romolo Tavani/Shutterstock)

Greeting Gentiles

As we all know, Christianity became almost entirely a non-Jewish faith. How did that happen? How did Gentiles take over a Jewish sect? It’s important to know because if they had not, the followers of Jesus, almost certainly, would not have taken over the world. 

The New Testament’s ‘book of Acts’ provides an explanation for how the transition happened. One might think it was all because of Paul, who called himself the Apostle to the Gentiles, and historically, that may actually be right, it may actually be because of Paul. And Acts itself does acknowledge that Paul played a significant role in taking the gospel to non-Jews. But, Acts also claims that it wasn’t Paul’s idea—it was God’s idea.

The way the book of Acts describes it, even before Paul began his mission to Gentiles, his predecessor Peter did. This is seen in a famous chapter that occurs right after Paul’s conversion in Chapter 9, but before he begins his mission. 

Peter’s Vision

Painting of Peter’s vision of a sheet filled with animals
Peter’s vision of a sheet filled with animals was a preface to introducing Christianity to Gentiles. (Image: Domenico Fetti/Public domain)

Chapter 10 describes a strange vision given to the Apostle Peter. Peter is on the top of a flat roof, praying, and he has a vision of a sheet that is filled with animals of all kinds, kosher and non-kosher, coming down from heaven.

He then hears a voice from heaven instructing him to eat the animals. That’s a real problem. Since, as a good Jew, he follows the laws of kosher, but now, God is telling him to eat the unclean food anyway. That’s a preface to what is to come.

The narrative of Acts shows that God wants to break down the barriers between Jews and Gentiles, as symbolized in this vision of non-kosher foods to be eaten. Peter is told to take the message of Christ to a non-Jew, a Roman centurion named Cornelius, who is a pious man, but who is uninstructed in the true faith. 

Peter is reluctant to go since he’s always believed that only Jews can properly worship the Jewish God. But Peter follows his divine orders, he speaks with Cornelius and the Gentiles with him; he proclaims to them the gospel and as he does so, the Spirit comes down upon them just as it did upon the Apostles themselves at Pentecost and the Gentiles convert. 

This article comes directly from content in the video series The Triumph of ChristianityWatch it now, on Wondrium.

Paul’s Valuable Contributions to God’s Idea

Peter then baptizes them and reports back to the other Apostles in Jerusalem that now Gentiles have begun to join the church. It’s not long after this that Paul goes on his first missionary journey, traveling to major cities outside of Palestine. 

In the narrative, Paul always makes his first stop in his missionary efforts at the local synagogue, but Jews in the synagogue repeatedly reject his message of the crucified messiah. And so, Paul is compelled to take his message outside the synagogue to Gentiles. And in every case, he finds the Gentiles far more receptive to his message.

Become Jewish to Become Christian

Portrait of Saint Paul
Paul’s missionary efforts mostly led him to preaching to Gentiles who were much more receptive to his message. (Image: Renata Sedmakova/Shutterstock)

Within the narrative of Acts, this conversion of Gentiles creates a huge conflict with other Christian leaders and the resolution of that conflict is one of the major themes of the book. Many of the original Jewish converts in the book insist that to follow the Jewish messiah, a person has to follow the Jewish law as given by the Jewish God. They are fine with Gentiles converting to this faith, but if somebody converts to believe in Jesus, the messiah, the person has to become Jewish. 

Paul and others in the book, including Peter, argued that, in fact, God has now shown that the gospel message can go to Gentiles as well as Jews and that accepting it does not require a person to become Jewish. That will seem common sense to most Christians today that, of course, a Christian doesn’t have to be a Jew, but the reason it’s common sense today is because of this battle at the very beginning of Christianity.

It is impossible to overemphasize the importance of the shift in Christian thinking in the earliest stages of its mission, a shift in which the message about Jesus moved from being an interpretation of Judaism to being open to all people: Jew and Gentile.

Christianity: No Longer a Jewish Sect

If Christianity had remained Jewish, insisting that its converts adopt Jewish ways and customs, including circumcision for men, kosher food laws, and sabbath observance for both men and women, there’s virtually no way it would have become a world religion. It would have stayed a sect within Judaism. A group of Jews who, unlike the others, claimed the messiah had already come. 

Christianity would almost certainly then have ended up having the historical impact and significance of any of the other Jewish sects from the time; for example, the Essenes who did not exactly take over the world. Christianity would have remained a small sect within a larger religion that itself was marginalized in its world.

Common Questions about How the Christian Movement Managed to Take Over the World

Q: How does the book of Acts explain Christianity opening its arms to anybody rather than only those who had adopted Jewish customs?

The book of Acts suggests that the idea of Gentiles joining the Christian movement was God’s. Right after Paul’s conversion but before he goes on his mission, Peter has a vision of breaking Jewish customs which signals what is to come.

Q: According to the book of Acts, how did Peter convert the Roman centurion, Cornelius?

God instructed Peter to convert Cornelius without the need for him to adopt Jewish customs. Though Peter was reluctant to convert a Gentile to the Christian movement, he did as God told him. As Peter was preaching to Cornelius, the Holy Spirit came upon Cornelius and he was converted on the spot.

Q: What would have happened if Christianity had remained Jewish?

If the Christian movement had remained an interpretation of Judaism, it wouldn’t have become a world religion. Rather, it would have remained a Jewish sect that believed the messiah had already come. Insisting that converts adopt Jewish customs, such as circumcision for men, would have never taken Christianity this far.

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