Why was Saul of Tarsus saved on the road to Damascus?
Saul of Tarsus was saved on the road to Damascus by the grace of God, not by any merit of his own. The account shows God stopped him in his tracks and saved him despite his religious zeal, before he understood the full gospel of Christ's death and resurrection; he had only recognized who Jesus really was.
Les explains that Saul of Tarsus was a religious Jew, a fanatic, and a zealot, but the grace of God stopped him in his tracks and saved him because he had no merit whatsoever—that is grace. On the road to Damascus Saul did not yet know that Christ died for his sins and had risen; that was not the basis yet. He had only recognized who Jesus really was. The account then returns to Acts chapter 9, where God deals with Ananias in a vision. The Lord tells Ananias to go to Straight Street, to the house of Judas, and inquire for Saul of Tarsus, who is praying and has seen a vision of Ananias coming and putting his hand on him so he might receive his sight. Ananias answers that he has heard by many how much evil Saul had done to the saints at Jerusalem. This underscores that Saul's salvation rested on God's grace, not his merit or prior understanding.