Christianity, as it is known today, is often seen as the religion founded by Jesus Christ. After all, the term “Christian” refers to followers of Christ, and Jesus is worshipped as the Son of God in Christian doctrine. However, a closer examination of historical texts and theological development reveals a compelling case: the foundations of Christianity were more firmly laid by the Apostle Paul than by Jesus himself. While Jesus provided the spiritual and moral core, it was Paul who transformed a small Jewish sect into a global religion.

Jesus the Teacher vs. Paul the Architect

Jesus of Nazareth was a Jewish preacher who taught in Galilee and Judea around 30 CE. His message centered on the Kingdom of God, repentance, love, and ethical living. He preached primarily to Jewish audiences, framed his teachings in Jewish law and prophetic tradition, and gave little indication of starting a new religion separate from Judaism.

In contrast, Paul—formerly known as Saul of Tarsus—emerged as a pivotal figure in the mid-1st century. Although he never met Jesus during his lifetime, Paul claimed a visionary experience of the risen Christ, which he interpreted as a divine commission to preach to the Gentiles. Through his missionary work, theological writings, and organizational efforts, Paul shifted the trajectory of the Jesus movement from a Jewish reform movement into a distinct, universal faith.

Jesus Preached a Kingdom, Paul Preached Christ

One of the starkest differences between Jesus and Paul lies in their respective messages. Jesus spoke frequently of the Kingdom of God—a transformative, imminent reality that would overturn the social and spiritual order. His teachings, such as the Sermon on the Mount, focused on ethical conduct, mercy, humility, and faithfulness. He emphasized obedience to God, love for neighbor, and inner purity, in line with the prophetic Jewish tradition.

Paul, on the other hand, rarely talked about the Kingdom of God in the way Jesus did. Instead, Paul focused on the person of Jesus—specifically, Jesus as the crucified and resurrected Messiah, whose death atoned for humanity’s sins. Paul's gospel was centered on salvation through faith in Christ, not merely following moral teachings or awaiting a coming kingdom.

In Galatians 2:16, Paul writes: "a person is not justified by works of the law but through faith in Jesus Christ." This represents a theological shift from Jesus’ own message, which emphasized action, righteousness, and spiritual vigilance. For Paul, belief in Jesus’s death and resurrection was the new path to salvation.

The Birth of Christian Doctrine

The earliest written Christian documents we possess are not the Gospels, but Paul’s letters (epistles), dated between 48 and 64 CE. These letters lay the groundwork for Christian theology, dealing with topics such as sin, grace, justification, atonement, resurrection, the Holy Spirit, and the role of the Church.

Key Christian doctrines—like original sin, salvation by grace, and the mystical body of Christ—are Pauline innovations. Jesus never outlined a doctrine of atonement or original sin in the Gospels. It was Paul who interpreted Jesus’s death as a cosmic sacrifice, echoing Jewish temple rituals, but giving them universal significance.

Romans 5:12-19 is a prime example. Paul compares Jesus to Adam, suggesting that just as sin entered the world through one man, salvation comes through another. This concept—central to Western Christianity—was unknown in Jesus’s own preaching but became a cornerstone of Christian theology through Paul.

Jesus the Jew, Paul the Founder of Christianity

Jesus lived and died as a Jew. He observed Jewish law, worshipped in synagogues, and referred to the Hebrew Scriptures. He did not seek to abolish the Law, famously stating in Matthew 5:17, "Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them."

Paul, however, de-emphasized the Jewish law, particularly for Gentile converts. He argued that circumcision, dietary laws, and Sabbath observance were not necessary for salvation. This was radical and controversial, leading to fierce debates with other apostles, including Peter and James, the brother of Jesus.

In Galatians 5:6, Paul writes: "For in Christ Jesus neither circumcision nor uncircumcision has any value. The only thing that counts is faith expressing itself through love." This opened the door for non-Jews to join the movement without adopting Jewish customs—a critical turning point in the emergence of a new religion.

The Institutional Church: Paul's Legacy

The structure of the Church, the role of apostles and bishops, and the concept of a global Christian community are largely Pauline constructs. Jesus gathered disciples and spoke of them as “fishers of men,” but he did not establish a church in any formal sense. The word "church" (Greek: ekklesia) appears only a few times in the Gospels.

Paul, however, established Christian communities throughout the Roman Empire—in places like Corinth, Ephesus, Philippi, and Thessalonica. He wrote to these communities, provided pastoral guidance, corrected theological errors, and urged unity under the banner of Christ. This network of churches was the embryonic form of the Christian Church, long before any council or pope emerged.

Paul also introduced the idea of the Church as the “Body of Christ”, a mystical union of all believers. This became a foundational metaphor for Christian identity and ecclesiology.

A New Religion Emerges

While Jesus may not have intended to start a new religion, Paul clearly understood that something new was happening. By welcoming Gentiles, redefining salvation, and promoting the risen Christ as divine Lord, Paul transcended the boundaries of Judaism.

Acts 11:26 tells us that it was in Antioch—one of Paul’s mission fields—that the followers of Jesus were first called “Christians.” This marks a transition: the movement was no longer simply a Jewish sect, but something distinct. Paul’s theology and missionary strategy played the central role in this transformation.

Conclusion: The Apostle Who Built the House

Jesus Christ remains the cornerstone of Christianity—the inspiration, the Savior, the moral exemplar. Without his life, teachings, and death, there would be no Christian movement at all.

But when we ask who built Christianity as an organized, theologically distinct religion, the answer is Paul. It was Paul who universalized the message, broke down ethnic and religious barriers, and developed the theological frameworks that defined Christian belief for centuries.

In the metaphor of a building: Jesus laid the cornerstone, but Paul constructed the house. Christianity as we know it—its doctrines, practices, and global identity—is more the product of Paul’s vision than Jesus’s original ministry.