The apostle who had the biggest influence on the development of Christianity is widely considered to be
Paul (formerly known as Saul of Tarsus).
Here's why:
* Extensive Missionary Journeys: Paul undertook several extensive missionary journeys throughout the Roman Empire, spreading the Gospel to Gentile (non-Jewish) communities. These journeys were crucial in establishing Christian communities outside of Judea.
* Theological Writings: Paul authored a significant portion of the New Testament, including letters (epistles) to various churches and individuals. These letters provided theological guidance, addressed practical issues, and helped to shape early Christian doctrine. His letters cover topics like justification by faith, the nature of the church, the importance of love, and the resurrection of Christ.
* Emphasis on Gentile Inclusion: Paul strongly advocated for the inclusion of Gentiles into the Christian faith without requiring them to adhere to Jewish law (circumcision, dietary laws, etc.). This was a controversial issue at the time, but Paul's position ultimately prevailed, paving the way for Christianity to become a universal religion.
* Interpretive Framework: Paul's interpretation of the life, death, and resurrection of Jesus Christ became a foundational framework for understanding Christian theology. He articulated key concepts like atonement, redemption, and the role of the Holy Spirit.
* Martyrdom: Paul's martyrdom is believed to have occurred in Rome during the reign of Emperor Nero, solidifying his status as a key figure in the faith and an example of commitment to Christ.
While other apostles like Peter and John were also important, Paul's impact was particularly significant in shaping the early church's theology, mission, and identity, ultimately leading to Christianity's widespread growth and development.