“And he said, "Who are you, Lord?" And he said, "I am Jesus, whom you are persecuting” (v5).  Saul/Paul knew Scripture, yet he was personally opposed to the Way (v2), the group of Jews who believed that Jesus was their Messiah.  Rather than seeing Jesus in the Old Testament, the way the Ethiopian did with Philip’s help, Paul was directly confronted with Jesus Himself, alive and powerful.  Then he was led to Ananias, who baptized him and welcomed him into the community of disciples (v19).  
While the Church saw Paul as enemy, God saw his potential as a “chosen instrument of Mine” (v15).  Totally transformed by grace, Paul began “preaching boldly” (v28) and risking his life for Jesus.