Paul was a member of the Jewish Pharisees in the 1st century CE, who experienced a revelation of the resurrected Jesus Christ. In this vision, Jesus commissioned him to be the apostle (herald) to the Gentiles (non-Jews). After this experience, he traveled widely throughout the Roman Empire, spreading the "good news" that Jesus would soon return from heaven and usher in the kingdom of God on earth.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/1841/the-letters-of-paul-the-apostle-to-the-gentiles/.