Acts 9:1-31
When Saul was first converted he still carried many of his habits, techniques and assumptions from his past thinking and training. He believed that over-powering arguments were the means to bring truth to other minds. He had always had a religion based on logic, study, facts and irrefutable proofs. Now he simply applied his new insights about Jesus and prophecies to continue his campaign to win everyone over to his viewpoint. Yes, his heart had been awakened by a fresh revelation of God in his vision from Jesus and his initial interactions with disciples in Damascus, but the habits of reasoning and his dependence on force of logic, if not physical force, would take time to undo. This is demonstrated both in Damascus and in Jerusalem much to the intense embarrassment of his former supporters to the point of death threats.
Evidently, from the text, while Saul was busy heating up the frustration and anger of his former close friends and comrades in religion, the leaders of the Christian church were spending time planting a new company in Caesarea and may not have been fully aware of what discontent and opposition Saul was stirring up in Jerusalem with his argumentative style. Saul was in danger of stirring up so much animosity against himself and the church that he was actually creating new zealots to replace the position of persecutor he had just vacated. He did not realize that it was unnecessary to use the tactics of forceful arguing and intimidation to spread truth. He had switched his allegiance but he had much to learn about gentleness and humility to reflect the true Spirit of Jesus in his labors.
The apostles realized the damage that Saul was beginning to induce on the church when they started receiving disturbing reports in Caesarea from Jerusalem and they may have decided to intervene before Saul inadvertently returned the situation to the reign of terror that he himself had so recently presided over. It was simply a problem of maturity, not ill motives. Saul was indeed converted, but his methods and spirit of presentation was sometimes abrasive and unnecessarily blunt.
So acting as mature elders would act, the apostles moved to intervene and brought Saul to Caesarea to where they could counsel with him about his methods and quietly discuss the problem so they could come up with a plan to help him move forward in true maturity and learn more of the true ways of Jesus. After careful consideration and prayer and closer bonding through affirmation it was mutually agreed that it would be best for Saul's growth at this point to allow him to return to his roots, his hometown and allow the Holy Spirit to have time to take him through an experience that would retrain him through the earliest stages of maturity so he would have a solid foundation for his future ministry.