What did Saul realize about Jesus and the God he thought he served?
Saul realized that Jesus, the one he thought he was trying to obliterate, was the very God he thought he was serving. He recognized he had been dead wrong about Jesus, and he became ready to serve Him instead of persecuting those who followed Him.
Les explains that Saul, later Paul, was outside Damascus in pitch darkness, not really knowing where he was going, with no explicit instructions beyond the fact that he would suffer for His name. Common sense might have sent him back to Jerusalem to look up Peter, James, and John, who had been with Jesus for three years and headed the group Saul had been trying to destroy. But Saul did not confer with flesh and blood. He had suddenly realized that the one he thought he was trying to obliterate was the very God he thought he was serving. He had been dead wrong about Jesus, and now he was ready to serve Him.