In his letter to the Galatians, chapter 1:15 to 2:1, Paul gives us some details of his conversion and what happened next, preparing him for his ministry and its beginning. This information completes the narration found in this passage, so we shall merge them where they seem most appropriate.
Saul was predestined and, by the grace of God, called to know the Son and to preach Him among the Gentiles (Galatians 1:15-16). Nevertheless, his first witness, after having spent several days with the disciples of Christ in Damascus, was to the Jews in the synagogues. It was to them that he had brought letters of recommendation from the Jewish religious authorities in Jerusalem, giving him authority to arrest and to take to Jerusalem any Christians he might find in Damascus.
These Jews were astonished to hear him announce that Jesus "is the Son of God" and it brought them consternation because they thought he had now become a traitor to his cause. However, Saul, beyond his personal experience, was able to prove through Scripture the truth of this identity, because he knew the Scriptures very well due to his studies. The Jews were confused.
Without consulting anyone, Saul travelled to "Arabia" (Galatians 1:17) – It was a large region, extending to the south from what is known today as Jordan. He does not give us more details, but it would have been an opportunity to prepare for the ministry among the Gentiles, among whom he found himself.
We do not know how long he was there, but Saul then returned to Damascus staying there for three years. During all this time, he had not met any of those who were already apostles before him, but even so he grew stronger in his ministry. His trip to Jerusalem was finally forced by circumstances created by the Jews, who became his enemies.
Saul learned of a plan drawn up by the Jews unanimously to kill him. He says, "In Damascus the governor, under Aretas the king, was guarding the city of the Damascenes with a garrison, desiring to arrest me" (2 Corinthians 11:32); they spent day and night watching the gates, but the disciples of Saul took him by night and let him down in a basket through an opening in the wall of the city.
Saul then went up to Jerusalem to meet Peter in person. This city was the most dangerous place he could be in, from the human point of view, but Saul was strengthened in his faith and knew that God would use him much more for His glory.
Upon arriving in Jerusalem Saul found, perhaps to his surprise that all the disciples were afraid of him, not believing that he really was a disciple of Jesus Christ. This distrust seems surprising, because after so long they should have already heard of his witness in Damascus. No doubt they thought they were unbelievable rumours, knowing how Saul had acted before, and judging that this might be a deception in order to catch them all.
His situation was precarious:
For obvious reasons Saul did not try to contact the Sanhedrin, who had sent him to Damascus. He had left as a hero in the defence of Pharisaism, but was returning as an apostate and a traitor in the eyes of the Pharisees.
He had escaped the conspiracy of the Jews in Damascus but now he found himself an object of the suspicion of disciples in Jerusalem, who had no proof of the sincerity of his conversion.
In this impasse, came Barnabas, a man mentioned at the very beginning of the story of the church in Jerusalem, when he sold a property and gave the proceeds to the apostles for distribution to the needy (chapter 4:36). Barnabas was a Levite converted to Christ, named Joseph, a native of Cyprus. The name Barnabas, which means "Son of Encouragement", was given him by the apostles because he always concerned himself with the welfare and spiritual benefit of others, especially in the Christian ministry.
We shall see further on that, sometime after the departure of Saul back to Tarsus, Barnabas was sent to Antioch by the Jerusalem church to encourage the church formed there with the dispersion of the believers in Jerusalem. Once there, Barnabas went to find Saul in Tarsus and brought him to Antioch to help in the teaching work (chapter 11:22,25).
Luke calls him a "good man" (Acts 11:24) and later on his name appears first in the list of prophets and teachers of the church formed in Antioch (cap.13:1). Barnabas was a companion of Paul on his first missionary journey.
Barnabas was acquainted with the situation in which Saul was in, and thought he was trustworthy person. There is the feasible and pleasing possibility that this well-educated man may also have been at the school of Gamaliel and there got to know Saul during his studies. It is just a hypothesis, but it could explain how he soon had contact with Saul, knowing him better than the others who only knew of his reputation as a persecutor of the church.
Barnabas lived up to his nickname taking Saul to the apostles. Paul informs us that of the apostles, he saw only Peter, but he also saw James the Lord's brother (who wrote the epistle that bears his name, and was one of the elders of the Jerusalem church, with Peter and other apostles). Barnabas told them about the circumstances of the conversion of Saul and how Saul had then proceeded to preach boldly in the name of Jesus.
With that Saul was well received by the brethren in Jerusalem, and stayed with Peter for fifteen days. Both Peter and James would have much to tell Saul about the Lord Jesus, because together they knew all His earthly life, His death, resurrection and ascension, and were personal witnesses of all these facts. Also during this time, for the tranquillity of Saul, he could walk freely in Jerusalem, where he went on to preach fearlessly in the name of the Lord.
It was a short visit, but it was proved that, although he had received the Gospel independently of the other apostles, it was the same Gospel that they preached - the gospel he had persecuted so fiercely before meeting with the Lord!
He also went to talk and discuss with the Greek-speaking Jews (as those who had persecuted Stephen - chapter 6:11), but these received him badly, and ended up trying to kill him. Knowing this, the brethren took him to the port of Caesarea and embarked him to Tarsus, where he came from. This city was in Cilicia, and Paul tells us that during the next fourteen years, he exercised his ministry in both Syria and Cilicia.
Paul informs that during all this time, he was not known by sight by the churches of Christ in Judea, but they had heard only, "He who formerly persecuted us now preaches the faith which he once tried to destroy." (Galatians 1:22-24.).
Earlier in his epistle to the Galatians, Paul began to defend his apostleship in view of the widespread opinion from Judaizing believers in that region, that he had not the same authority as the apostles who were with Jesus during His ministry, while questioning if he was a genuine apostle. The same happened in Corinth, causing the most violent expression of irony on the part of Paul: see in 2 Corinthians 10 and 12.
Paul denies bluntly that he was an apostle "from men or through man, but through Jesus Christ and God the Father who raised Him from the dead" (Gal 1:. 1).
Paul proves his independence from the rest of the apostles in the text studied here, and his equality with them was recognized by them. His appointment as an apostle was made by Jesus Christ himself (like the other apostles) and by God the Father. He is an apostle equally by the will of the Son and of the Father, having seen the risen Christ as well as others.
21 Then all who heard were amazed, and said, "Is this not he who destroyed those who called on this name in Jerusalem, and has come here for that purpose, so that he might bring them bound to the chief priests?"
22 But Saul increased all the more in strength, and confounded the Jews who dwelt in Damascus, proving that this Jesus is the Christ.
23 Now after many days were past, the Jews plotted to kill him.
24 But their plot became known to Saul. And they watched the gates day and night, to kill him.
25 Then the disciples took him by night and let him down through the wall in a large basket.
26 And when Saul had come to Jerusalem, he tried to join the disciples; but they were all afraid of him, and did not believe that he was a disciple.
27 But Barnabas took him and brought him to the apostles. And he declared to them how he had seen the Lord on the road, and that He had spoken to him, and how he had preached boldly at Damascus in the name of Jesus.
28 So he was with them at Jerusalem, coming in and going out.
29 And he spoke boldly in the name of the Lord Jesus and disputed against the Hellenists, but they attempted to kill him.
30 When the brethren found out, they brought him down to Caesarea and sent him out to Tarsus.
Acts chapter 9 verses 21 to 30