Paul watched the killing of Stephen, the first martyr. He did everything he could to stamp out the new Christian church. We would not expect him to become a convert, missionary and apostle, but that is what God did. After Paul knew that Jesus was the Christ, the Son of God, his first action was to tell others. Everyone who wants a vital spiritual life must do the same - we must know Jesus and tell others.
Peter loved and followed Jesus, and even though he denied Christ, Peter was forgiven and followed his Lord for the rest of his life. Indeed, we see how he preached in Jerusalem and withstood the authorities who tried to silence him. God sent Peter to Cornelius, the gentile, which let Peter and everyone know that the good news was for all people. Peter ate with the unclean gentiles and his actions made a point - the Gospel is for everyone who believes.
(8 messages on 4 CDs)