What does Acts 9:12 mean?
Ananias is a Jesus-follower in Damascus who knows about the Saul who initiated the violent persecution of the church (Acts 8:1–3; 9:1–2). Because Saul later refers to him as "devout" (Acts 22:12), he may be a Gentile who worshiped the Jewish God before he became a Christian. He is not the husband of Sapphira (Acts 5:1–6) or the future high priest whom Saul will offend (Acts 23:2; 24:1).Despite living 133 miles from Jerusalem, Ananias is still nervous that Saul, under the authority of the Sanhedrin, is coming to Damascus to arrest Jesus-followers. Now, Jesus is telling him that Saul has reached the city and he needs to find him. On the road to Damascus, Jesus appeared to Saul in a blazing light and asked him why he was persecuting Him (Acts 9:1–9). For the last three days, Saul has been in a house, fasting from food and drink, and praying.
What's more, Saul is blind, and Jesus wants Ananias to heal him. Healing the blind is a miracle that is particularly associated with the Messiah (Isaiah 42:7). Only Jesus is credited with healing of blindness in Scripture—including here, where Ananias acts as something of a surrogate or conduit for Christ's healing. If Saul has any doubt about who Jesus is, this healing will end it. But Ananias needs more convincing.