Paul was a Jew, an educated Pharisee, tutored by Gamaliel who was a member of the Jewish ruling council.  He was devout from childhood, keeping all the small rules of his religion (Acts 26:4-5).  He was present when Stephen was stoned and approved of his execution (Acts 22:20).  He believed that the concept of Jesus as the Son of God was blasphemous, and that God, and his religious superiors, would be pleased if he could arrange for people following Jesus to be punished or killed (Acts 26:9-11).  It was his religious duty to eradicate such nonsense (1 Timothy 1:13).  The wave of persecution which Paul had encouraged was violent and indiscriminate – men and women who believed in Jesus were liable to face beatings, prison and death (Acts 26:10-11).
 
The change in Paul’s life came when Jesus revealed Himself as the Lord and Messiah (Acts 26:12-18).  When Jesus spoke to him directly, Paul knew that Jesus was awesomely powerful with an enduring divine personal identity.  That encounter was God’s gracious call.  Although Paul had been brought up to believe that God had called him, it was only a religious concept until Christ’s call came personally - then he knew that he must obey the Lord he had been fighting.
 
Paul did not need more theological learning.  He simply needed to get to know Jesus Christ, agreeing that Jesus was right and he was wrong.  He had so much wrong thinking to unlearn and Jesus tutored him in understanding how the Old Testament Scriptures all pointed towards Himself (1 Corinthians 15:3-4).  Instead of a religion based on keeping all the rules, Paul found that Jesus wanted a dynamic relationship with him.  Instead of pretending to be holy, it was safe for Paul to admit his sins and to ask for forgiveness (Romans 7:21-25).  Instead of working to earn God’s favour, Paul learned that he simply needed to receive the grace Jesus offered (Ephesians 2:3-9).

We cannot argue people into the Kingdom of God, but we can and must tell out the gospel message and explain the identity of Jesus.  He, and His cross, is the key to eternity.  God uses the gospel information, which believers should scatter like seed.  That Word of truth convinces people that Jesus is the Son of God - who has the power to save and give new life, as well as the authority to judge those who refuse His call.  Sharing that information and persuading people to examine it is the responsibility of each believer: revealing the identity of Jesus to a sinful heart is God’s.  So we have a work to do alongside God, trusting Him to show Himself and draw people to submit to His authority.