Why was Saul of Tarsus converted?
Saul of Tarsus was converted by God's grace on the road to Damascus to serve as the apostle of the Gentiles. After Israel's stumbling, God raised up this one zealous Jew to carry salvation primarily to Gentiles, though he also ministered to Jews.
Les explains that Israel stumbled over their Messiah, but God did not completely cast them off. Through their fall, salvation came to the Gentiles under a different format. Instead of using the whole nation of Israel as priests to bring Gentiles to Jehovah, God raised up one Jew, Saul of Tarsus, a renegade zealous for the law, and saved him by grace on the Damascus road. God's first message to Saul was that He would send him far hence to the Gentiles. Saul would also go to the Jew, but he was primarily the apostle of the Gentiles, converted for that purpose.