Who are you, Lord? I am Jesus the Nazorean, whom you are persecuting. The Church commemorates today the conversion of Saul of Tarsus, one of the most touching events in the history of the early Church. It is a story that is recounted more than once in the Acts of the Apostles, the first time as part of the developments in the early Church (cf. Acts 9:1ff), and then later on by Paul himself as part of his defense (cf. Acts 22:1-11, 26:12-18). 
In Paul's address to the Jerusalem Jews as he was being led away following his arrest (cf. Acts 22:1ff), Paul narrates the events that led to him embracing the Christian faith, a  cult he had fiercely persecuted. Paul says that his actions against the Christians were not driven out of malice but rather because he was  zealous for God. He felt that it was his duty to see to the preservation of the faith of his ancestors. This became his mission until he encountered Jesus the Nazorean. While we might not know the full details of what went on inside of him during and after his encounter with Christ that made him to make such a drastic turn-around in his faith life, there is one thing that clearly stands out, something that is central to the Christian faith. Because Paul could not keep up the count of those he had put to prison, he probably wanted to know who among the many he had persecuted was speaking to him during the vision. He got an answer, but probably not one that he had expected: “I am Jesus the Nazorean whom you are persecuting .”As far as we are aware, Paul never personally encountered Jesus during his (Jesus’) years of ministry. Jesus had been dead for twenty or so years by the time Paul was leading the fierce persecution against the  Way.Jesus was dead, he knew it, and everybody knew it. Yet, it was this very Jesus that Paul was persecuting. This, among many, must have contributed to Paul  re-thinking his stance.
"I will be with you till the end of time," Jesus had promised his disciples while he was still with them. And in Jesus’ response to Paul, we see him making true of this promise. Jesus does not tell Paul that  I am the founder of the Way that you are persecuting. He does not tell Paul that  I am the leader of this group you are fighting. No. Jesus identifies with his persecuted disciples. He tells Paul:  I am the Way that you are persecuting; I am this group that you are persecuting. You have not been persecuting James or Peter or John. You have been persecuting Jesus of Nazareth. Upon encountering Jesus, Paul becomes a changed man. He is never the same after this encounter. His whole life becomes turned upside down. What had made sense to him earlier ceases to be so. He embarks on a journey, a journey that will test his limits. But he will be able to pass the tests, because he believed that what Jesus had said about his disciples whom Paul had persecuted, would also apply to him. Jesus was going to be with him to the end.