Conversion is a miraculous act of God in the human heart. A. Technically, there are not many miracles being done now, such as we find in Bible stories. B. Conversion is a true miracle. We are dead in trespasses and sins. The Holy Spirit makes us born again.
Conversion is a life-changing experience.
Obviously so in Paul's case. We have been made different. Our lives changed. He will if you believe in Him. God wants experienced Christians to disciple newer Christians.