Jesus spoke to Ananias in a vision: Go tell Saul to tell about me to both Gentiles and Jews.
Ananias was surprised at the choice of Saul because of his efforts at ridding Judaism of Christ followers. But, he expressed no surprise at the message only the messenger. After all, Jesus himself had reached out to many persons who were not faithful Jews--or any kind of Jew--for example, sinners, collaborators, and foreigners.
Jesus is still reaching out. It is ironic that he would choose Saul for the mission. Saul, who had been trying to rid the Jews of those who were adherents to Christ, is now going to be asked to go to people who aren't even Jews.
Ananias was afraid and had reason to be; yet, he does what the Lord tells him to do--approach this man who has been persecuting people like him.
He did what Jesus had told him to do. Immediately Saul's sight was restored. He got up, was baptized, ate some food, got stronger, and begin to proclaim Jesus in the synagogues, saying "He is the Son of God."