Acts 9:26-31 meaning

According to Saul's testimony in his letter to the Galatians, he spent three years in Arabia before going back to Jerusalem (Galatians 1:17). Arabia at that time would not mean the modern region of Saudi Arabia. It did not exist yet. The general consensus is that it was the Kingdom of the Arab Nabataeans, a region to the east of Judea. The Bible doesn't describe what Saul did in those three years, but presumably he was obeying Christ and spreading the gospel to the Nabataeans.

Luke, the author of Acts, does not address this period, but writes of what happened when Saul ultimately went back to Jerusalem. He likely leaves this out because his objective in writing Acts is to validate Paul's authority as an apostle of Jesus.

When Saul came to Jerusalem, he tried to make friends with the other believers in Jesus, just as he had in Damascus: he was trying to associate with the disciples; but they were all afraid of him, not believing that he was a disciple. The disciples here include the general group of believers and followers of Christ. The twelve disciples who followed Jesus closely during His ministry, as reported in the Gospels, are called the apostles throughout Acts.

So for a brief period of time, Saul approached other believers, disciples, trying to associate with them, but they were afraid and did not believe he was sincerely a disciple. Their reaction is understandable. Saul had broken up the church in Jerusalem years before (Acts 8:1), had put their friends in prison, possibly leading to some deaths. The last they heard of Saul, he had disappeared from the scene in Damascus, and had probably not been heard of for some time. Now he appears in Jerusalem again, claiming to believe in Jesus. It is not unreasonable that they thought he was lying, that he was trying to infiltrate the church of Jerusalem that had rebuilt from the wreckage which he had caused.

A familiar name reappears in Luke's narrative. A man formerly called Joseph, who was renamed "Son of Encouragement" by the apostles: Barnabas. He "owned a tract of land, sold it and brought the money and laid it at the apostles' feet" (Acts 4:37). Luke characterizes Barnabas as a magnanimous man, full of faith, not driven by fear, someone who sees the good in others and tries to cultivate it. We can see this in his name, Son of Encouragement, and his charitable givings to the church, as well as his desire to bring the young John Mark on a future missionary journey, even though John Mark proved unreliable in the past (Acts 15:36-39).

Here, Barnabas gives Saul a chance to explain himself, which leads to Saul's acceptance as one of the brethren in Christ: But Barnabas took hold of him and brought him to the apostles. Saul is able to give his testimony to the apostles: he described to them how he had seen the Lord on the road, and that He had talked to him, and how at Damascus he had spoken out boldly in the name of Jesus. 

Since Barnabas was someone the community of believers trusted, his vouching for Saul was key to the church receiving him. This pair, Barnabas and Saul, will soon become ministry partners for their first missionary journey (Acts 13:2).

Saul, in his letter to the Galatians, provides some extra details of this return to Jerusalem. In fact, it was very brief, and he only met two of the apostles:

"I went up to Jerusalem to become acquainted with Cephas [Peter], and stayed with him fifteen days. But I did not see any other of the apostles except James, the Lord's brother."
(Galatians 1:18-19)

We don't know how many days he spent in Jerusalem before meeting the apostles, but once he became acquainted with Peter, Saul stayed with him for only two weeks, before leaving.

Here in Acts 9, Luke's explanation for why Saul had to flee Jerusalem was due to threats of death from the Hellenistic Jews. The Hellenistic Jews were Greek-speaking Jews. Some were believers in Jesus, from the start of the Jerusalem church when Peter preached at the festival of Pentecost (Acts 2:9-12). There was tension between the believing Hellenistic Jews and the believing native Hebrew Jewish believers which led to the formation of the Deacons (Acts 6:1-6).

Saul was talking and arguing with the Hellenistic Jews; but they were attempting to put him to death. Based on Saul's testimony of his first return to Jerusalem in Acts 22, he says that Christ warned him in a vision that there was a desire for vengeance against him:

"It happened when I returned to Jerusalem and was praying in the temple, that I fell into a trance, and I saw Him saying to me, 'Make haste, and get out of Jerusalem quickly, because they will not accept your testimony about Me.' And I said, 'Lord, they themselves understand that in one synagogue after another I used to imprison and beat those who believed in You. And when the blood of Your witness Stephen was being shed, I also was standing by approving, and watching out for the coats of those who were slaying him.' And He said to me, 'Go! For I will send you far away to the Gentiles.'"
(Acts 22:17-21)

So while Saul had been accepted by Barnabas and the Apostles Peter and James (Jesus's brother, author of the book of James), the Hellenistic Jews were determined to eliminate him. Jesus warns him to quickly leave Jerusalem, because they, the Greek-speaking Jews, are dedicated to kill him. So Christ tells Saul to depart, and to pursue ministry among the Gentiles, the non-Jews.

Here in Acts 9, Luke tells us that the brethren also learned of this attempt to put Saul to death. It is possible that Saul told Peter, with whom he was staying, of his vision. Barnabas and James may have heard rumors and reports of this death threat from others. So they sent Saul out of Jerusalem, and brought him safely down to Caesarea, a coastal city built by King Herod the Great on the Mediterranean Sea, and sent him away by boat to his hometown of Tarsus (see map in Additional Resources ). He is said to be brought down to Caesarea even though Caesarea is north of Jerusalem, because down refers to elevation. Generally the Bible speaks of going up to Jerusalem. An example are the "psalms of ascents," written for pilgrims as they ascended to Jerusalem (Psalms 120-134).