Paul, also known as Saint Paul, was a pivotal figure in the early development of Christianity. Originally a persecutor of Christians, he underwent a profound transformation after a visionary experience on the road to Damascus, leading him to become one of the most influential apostles spreading the teachings of Jesus Christ. His letters, known as the Epistles, form a significant part of the New Testament and provide insight into the beliefs and practices of early Christians. Paul's missionary journeys across the Roman Empire helped establish numerous churches and spread the message of Christianity far and wide.