Summary: The remarkable conversion of Saul, in which he put his faith in the Savior he had been so viciously persecuting, unfolds in five phases: 1) Contact (Acts 9:3), 2) Conviction (Acts 9:4), 3) Conversion (Acts 9:5), 4) Consecration (Acts 9:6–8), and 5) Communion (Acts 9:9).
Acts 9:1-9  But Saul, still breathing threats and murder against the disciples of the Lord, went to the high priest  and asked him for letters to the synagogues at Damascus, so that if he found any belonging to the Way, men or women, he might bring them bound to Jerusalem.  Now as he went on his way, he approached Damascus, and suddenly a light from heaven flashed around him.  And falling to the ground he heard a voice saying to him, "Saul, Saul, why are you persecuting me?"  And he said, "Who are you, Lord?" And he said, "I am Jesus, whom you are persecuting.  But rise and enter the city, and you will be told what you are to do."  The men who were traveling with him stood speechless, hearing the voice but seeing no one.  Saul rose from the ground, and although his eyes were opened, he saw nothing. So, they led him by the hand and brought him into Damascus.  And for three days he was without sight, and neither ate nor drank. (ESV)
The famous football coach of the University of Alabama, Paul “Bear” Bryant, once gathered all his coaches together for a meeting. He told them, “There are different kinds of boys out there and we don’t want all of them playing football at Alabama. There is one kind of boy who gets knocked down and stays down. We don’t want him at Alabama. There is another boy who gets knocked down and gets up. But if you knock him down again, he stays down. We don’t want that boy at Alabama. But there are some boys that you can knock down and they get up. You can knock them down over and over again and they will always get up.” One of the assistant coaches piped up, “That’s the kind of boy we want at Alabama, isn’t it coach?” “No,” said Bear, “We want the boy that’s knocking the others down.” … So, it is somewhat surprising who God wants on his team to evangelize the world. If you were selecting missionaries in the first century, you would never pick Saul of Tarsus. Saul was the church’s number one enemy. Saul grew up a Pharisee in Tarsus—a Roman citizen in a Roman city. His parents were so devoted that they sent Saul to Jerusalem to study with the renowned rabbi Gamaliel. There, Saul was valedictorian. He was the brightest hope for leadership among the Pharisees. Like most Pharisees, Saul supported the crucifixion of Jesus. When Jesus’ disciples began to preach that Jesus was risen from the dead and was indeed both Lord and Messiah, Saul was infuriated. Saul even led the troops at the assassination of Stephen (Acts 7:58). He became the High Priest’s point man for the systematic de-Christianization of Jerusalem. (Bouchelle, D. (2005). Acts 1–9: The Gospel Unleashed (pp. 91–92). Joplin, MO: HeartSpring Publishing.)
The first two verses (of Acts 9) provide the chronological and geographical setting. More significantly, they picture the preconversion Paul, which contrasts radically with the picture of Paul after the encounter on the Damascus road. Acts 9:1 picks up the picture in 8:3. Paul was still the church’s number one enemy, still raging against it (Polhill, J. B. (2001). Vol. 26: Acts (electronic ed.). Logos Library System; The New American Commentary (233). Nashville: Broadman & Holman Publishers.) Saul (his preconversion name), Luke notes in verse 1, was still breathing threats and murder against the disciples of the Lord. Persecuting Christians consumed him; it had become his whole life. The very air he was breathing was that of threats and murder against the disciples of the Lord. The word “murder” is significant. The fact that he had succeeded in having others (besides Stephen) put to death is certain. The term disciples refers to all believers, not merely the twelve apostles. Every Christian is a follower of and learner from the Lord Jesus Christ. Saul wanted every one he could lay his hands on. (Lenski, R. C. H. (1961). The Interpretation of the Acts of the Apostles (350). Minneapolis, MN: Augsburg Publishing House.).
Hearing of a group of Christians in Damascus, Saul driven by deadly ambition and twisted religious zeal, went to the high priest, and as it says in Acts 9:2, asked him for letters to the synagogues at Damascus, so that if he found any belonging to the Way, men or women, he might bring them bound to Jerusalem. The high priest, here was acting in his capacity as president of the Sanhedrin. The Roman government allowed the Sanhedrin to exercise jurisdiction over Jews living outside of Palestine. Saul’s intention was to bring those who belonged to the Way to Jerusalem as captives, to be tried by the Sanhedrin. For that purpose, he asked for credentials that would give him the authority to do so. He planned to go to the synagogues because that was where Jewish followers of Jesus would be worshiping. They were Jews who believed that their Messiah had come. They would not stop worshiping with their fellow Jews until it became clear that they (and Jesus’ name) were no longer welcome. (Balge, R. D. (1988). Acts. The People's Bible (99). Milwaukee, Wis.: Northwestern Pub. House.).