When the Bible introduces us to Paul, we are witnessing an angry mob stoning Stephen. Stephen had just told his fellow Jews that they were missing the salvation of the Messiah, because they refused to let go of their buildings and traditions. They believed that their building (the temple) and their traditions (the law of Moses) were what would save them, but Stephen told them that these were only meant to point to the true salvation that would come through Jesus. This is why they dragged him outside the city and began hurling stones at him until they had killed him. Saul agreed wholeheartedly with what they were doing and volunteered to watch everyone’s coats while they threw stones at Stephen. After all, who wants to have a coat getting in the way of a good wind up on a stone. After Stephen’s death, the persecution of the church in Jerusalem reached a white-hot intensity, and Saul was one of its greatest leaders.
I suspect that if you were to ask Christians at that time to pick a person that they expected God to use to write most of the New Testament and to plant churches all over the Mediterranean world, none of them would have picked Saul of Tarsus. God is just so much more imaginative than we are. Please never forget that things that are absolutely impossible for us are absolutely certain for God.