For Christians, Paul/Saul of Tarsus is a character of biblical proportions! He indisputably wrote 7 epistles, probably sometime between 50 and 60 CE: 1 Thessalonians; Galatians; Philippians; 1 and 2 Corinthians; Philemon and Romans. Paul's theology influenced 2 Thessalonians, Ephesians and Colossians, all 3 authored around 90 or 100 CE. In addition, the chronologically later letter to the Hebrews (circa 90 CE) bears unmistakable marks of Pauline theology and Christology. However, scholars today generally do not consider the pastoral epistles traditionally attributed to him as genuine Paul. 1 Timothy, 2 Timothy and Titus (possibly from as late as 125 CE) are socially very conservative, with language and content that at times directly contradicts what we find in the authentic letters. Particularly since the Reformation of the 16th century, most Christians are "Pauline" Christians at least to as great an extent they are Jesus Christians!
In their work on multicultural evangelism, Latino theologians Justo Gonzalez and Miguel De La Torre both point out Paul's name didn't "change" from Saul to Paul upon his conversion to Christianity but rather Saul was Paul and Paul was Saul - and Saul/Paul concurrently with "Saul" and "Paul" probably had at least two or three other names.
Since we're studying biblical personalities, here's a little about the apostle Paul: we know from reading Paul's undisputed letters and from the book of Acts that Paul was multicultural - Roman, Greek and Hebrew/Jewish, which made him sensitive and responsive to the differences between cultures, and also aware that the Church would take differing expressions in different places. From the epistles we know how strongly Paul ran with his convictions, never backing down and always telling his readers and his listeners about the life-changing power of the Gospel and especially about the weakness of the Cross of Calvary that is human foolishness and divine wisdom. Paul was far more theologian than biblical scholar or scriptorian, though only Romans, which essentially is his systematic theology, has much of what anyone would consider "system!" Lots of detours and many ramblings are hallmarks of his correspondence. There's some thought the author of Luke/Acts was Paul's amanuensis.
32Now the whole group of those who believed were of one heart and soul, and no one claimed private ownership of any possessions, but everything they owned was held in common. 33With great power the apostles gave their testimony to the resurrection of the Lord Jesus, and great grace was upon them all. 34There was not a needy person among them, for as many as owned lands or houses sold them and brought the proceeds of what was sold. 35They laid it at the apostles’ feet, and it was distributed to each as any had need. 36There was a Levite, a native of Cyprus, Joseph, to whom the apostles gave the name Barnabas (which means “son of encouragement”). 37He sold a field that belonged to him, then brought the money, and laid it at the apostles’ feet.
26When he had come to Jerusalem, he attempted to join the disciples; and they were all afraid of him, for they did not believe that he was a disciple. 27But Barnabas took him, brought him to the apostles, and described for them how on the road he had seen the Lord, who had spoken to him, and how in Damascus he had spoken boldly in the name of Jesus.
19Now those who were scattered because of the persecution that took place over Stephen traveled as far as Phoenicia, Cyprus, and Antioch, and they spoke the word to no one except Jews. 20But among them were some men of Cyprus and Cyrene who, on coming to Antioch, spoke to the Hellenists also, proclaiming the Lord Jesus. 21The hand of the Lord was with them, and a great number became believers and turned to the Lord. 22News of this came to the ears of the church in Jerusalem, and they sent Barnabas to Antioch. 23When he came and saw the grace of God, he rejoiced, and he exhorted them all to remain faithful to the Lord with steadfast devotion; 24for he was a good man, full of the Holy Spirit and of faith. And a great many people were brought to the Lord. 25Then Barnabas went to Tarsus to look for Saul, 26and when he had found him, he brought him to Antioch. So it was that for an entire year they met with the church and taught a great many people, and it was in Antioch that the disciples were first called “Christians.”
27At that time prophets came down from Jerusalem to Antioch. 28One of them named Agabus stood up and predicted by the Spirit that there would be a severe famine over all the world; and this took place during the reign of Claudius. 29The disciples determined that according to their ability, each would send relief to the believers living in Judea; 30this they did, sending it to the elders by Barnabas and Saul.
36After some days Paul said to Barnabas, “Come, let us return and visit the believers in every city where we proclaimed the word of the Lord and see how they are doing.” 37Barnabas wanted to take with them John called Mark. 38But Paul decided not to take with them one who had deserted them in Pamphylia and had not accompanied them in the work. 39The disagreement became so sharp that they parted company; Barnabas took Mark with him and sailed away to Cyprus. 40But Paul chose Silas and set out, the believers commending him to the grace of the Lord. 41He went through Syria and Cilicia, strengthening the churches.